[System] You are a network routing expert. Analyze the routing table, detect issues, and provide step-by-step reasoning. Use the format: <reasoning>...step-by-step analysis...</reasoning><answer>...concise answer...</answer>

[User]
Routing table:
O    10.32.186.0/28 [110/9] via 192.168.238.70, 06:11:53, Port-channel1
O    10.40.89.0/24 [110/113] via 192.168.104.231, 00:00:27, Port-channel1
O    10.165.154.0/17 [110/9] via 192.168.231.173, 06:05:10, Serial1/1:1
O    10.248.134.0/29 [110/5] via 192.168.248.221, 21:26:35, Port-channel7
O    10.18.187.0/23 [110/10] via 192.168.161.84, 00:31:14, GigabitEthernet0/2
C    192.168.1.0/24 is directly connected, GigabitEthernet0/0
O    10.40.89.0/24 [110/4] via 192.168.63.30, 00:00:14, GigabitEthernet3/0
O    10.207.197.0/16 [110/5] via 192.168.138.16, 08:48:52, Serial3/0:0
O    10.101.60.0/20 [110/8] via 192.168.176.1, 09:01:56, Serial1/0:0
O    10.42.176.0/23 [110/10] via 192.168.101.205, 06:09:29, Port-channel2
O    10.253.28.0/22 [110/5] via 192.168.116.69, 07:47:56, Port-channel1
O    10.167.102.0/24 [110/7] via 192.168.58.214, 07:17:29, Port-channel7
O    10.88.255.0/30 [110/6] via 192.168.42.150, 08:50:14, Loopback20
O    10.43.251.0/23 [110/15] via 192.168.141.65, 19:10:23, Serial0/0:0
O    10.87.201.0/29 [110/3] via 192.168.214.121, 04:46:30, FastEthernet3/2
L    192.168.1.1/32 is directly connected, GigabitEthernet0/0
O    10.36.75.0/23 [110/7] via 192.168.246.151, 15:03:05, Loopback22

Question: Does this routing table have any routing inconsistencies?

[Assistant]
<reasoning>
1. Observation: Two OSPF routes to 10.40.89.0/24 exist with different metrics: 4 via 192.168.63.30 (recent) and 113 via 192.168.104.231 (more recent). The metric oscillated by 109 within 30 seconds.
2. Analysis: Metric flapping in OSPF indicates interface cost instability. Possible causes: (a) interface bandwidth auto-negotiation flapping between speeds (e.g., 1Gbps ↔ 100Mbps), (b) reference bandwidth change on an upstream router, (c) LSA refresh from a router with inconsistent cost, or (d) a link with intermittent congestion causing OSPF to recalculate.
3. Context: Metric flapping triggers repeated SPF calculations, consuming CPU. It also causes route churn in the RIB and FIB, leading to packet loss and out-of-order delivery. CEF may alternate between next-hops, causing micro-looping.
4. Recommendation: Check interface speed/duplex on all links toward 10.40.89.0/24 with 'show interface'. Verify 'auto-cost reference-bandwidth' is identical on all routers in the area. Check for LSA Type 1/2 flooding storms. Consider enabling OSPF SPF throttling ('timers throttle spf') to dampen recalculation frequency.
</reasoning>
<answer>
WARNING: OSPF metric flapping for 10.40.89.0/24. Metric oscillated between 4 and 113 within 30 seconds. Check interface speed/duplex negotiation, reference-bandwidth consistency, and LSA flooding. Enable SPF throttling to reduce CPU impact.
</answer>


[System] You are a network routing expert. Analyze the routing table, detect issues, and provide step-by-step reasoning. Use the format: <reasoning>...step-by-step analysis...</reasoning><answer>...concise answer...</answer>

[User]
Routing table:
B    10.171.136.0/27 [20/1] via 192.168.235.72
B    10.31.96.0/30 [20/2] via 192.168.148.226
B    10.119.216.0/26 [20/3] via 192.168.199.176
B    10.57.190.0/19 [20/13] via 192.168.92.27
L    192.168.1.1/32 is directly connected, GigabitEthernet0/0
B    10.22.92.0/22 [20/7] via 192.168.126.240
B    10.220.60.0/23 [20/6] via 192.168.232.182
B    10.97.199.0/21 [20/6] via 192.168.214.246
B    10.26.163.0/20 [20/9] via 192.168.3.171
B    10.61.120.0/19 [20/5] via 192.168.50.122
C    192.168.1.0/24 is directly connected, GigabitEthernet0/0
B    10.168.144.0/23 [20/3] via 192.168.243.171
B    10.111.96.0/23 [20/10] via 192.168.144.196
B    10.1.156.0/24 [20/1026] via 192.168.201.25

Question: Analyze this routing table for Administrative Distance conflicts.

[Assistant]
<reasoning>
1. Observation: BGP route to 10.1.156.0/24 has MED 1026, while all other BGP routes have MED between 0 and 15. The MED deviation is 68x to 1026x from the normal range.
2. Analysis: MED (Multi-Exit Discriminator) is used for inter-AS path selection when multiple paths exist from the same neighboring AS. A MED of 1026 is atypical—normal MED values reflect IGP cost (usually <1000). This extreme value suggests: (a) IGP metric redistribution without scaling, (b) manual MED policy misconfiguration, (c) AS-path prepending combined with MED, or (d) a BGP community setting MED incorrectly.
3. Context: BGP best-path selection compares MED after weight, local-preference, and AS-path length. An extreme MED makes this path the least preferred among equal AS-path alternatives, effectively black-holing traffic if it's the only path. It also complicates traffic engineering.
4. Recommendation: Verify MED configuration on the advertising router. Check route-maps setting MED based on IGP metric—consider dividing by a factor (e.g., 'set metric igp-cost / 10'). Review BGP communities that manipulate MED. Ensure consistent MED policy across all BGP speakers in the AS.
</reasoning>
<answer>
WARNING: BGP MED skew for 10.1.156.0/24. MED 1026 is 68x–1026x higher than normal (0–15). Check IGP redistribution scaling, route-map MED policies, and community configurations. Path likely depreferred.
</answer>


[System] You are a network routing expert. Analyze the routing table, detect issues, and provide step-by-step reasoning. Use the format: <reasoning>...step-by-step analysis...</reasoning><answer>...concise answer...</answer>

[User]
Routing table:
O    192.168.82.0/24 [110/41] via 192.168.72.209, 03:06:34, Port-channel3
L    192.168.1.1/32 is directly connected, GigabitEthernet0/0
B    10.105.76.0/16 [20/39] via 192.168.176.235
C    192.168.1.0/24 is directly connected, GigabitEthernet0/0
B    10.148.120.0/16 [20/16] via 192.168.56.55
O    10.95.214.0/24 [110/13] via 192.168.54.169, 14:14:32, Loopback86
O    10.34.154.0/23 [110/16] via 192.168.125.41, 21:38:27, FastEthernet1/0
B    10.235.253.0/21 [20/2] via 192.168.99.16
O    10.228.85.0/16 [110/5] via 192.168.245.110, 12:28:18, Port-channel5
O    10.180.162.0/27 [110/9] via 192.168.17.198, 03:23:27, Loopback67
O    10.228.233.0/21 [110/18] via 192.168.184.39, 21:44:23, Port-channel3
O    10.112.208.0/30 [110/10] via 192.168.122.12, 04:53:59, Port-channel5
B    10.35.214.0/24 [20/1220] via 192.168.82.53
B    10.83.43.0/23 [20/13] via 192.168.168.139

Question: Identify all potential issues in this routing table and classify them by severity.

[Assistant]
<reasoning>
1. Observation: BGP route to 10.35.214.0/24 has MED 1220, but the IGP (OSPF) metric to its next-hop 192.168.82.53 is only 41. The MED is 29x to 1220x higher than the actual IGP cost.
2. Analysis: MED should ideally reflect the IGP metric from the advertising router to the BGP next-hop. A large discrepancy indicates: (a) MED is manually set without IGP correlation, (b) IGP metric changed after BGP advertisement, (c) redistribution from another protocol with different metric scale, or (d) route-map setting MED based on a static value rather than dynamic IGP.
3. Context: Inconsistent MED-to-IGP mapping breaks hot-potato routing. Traffic may enter the AS at a suboptimal point because MED doesn't reflect true internal cost. This causes inefficient inter-domain traffic patterns and violates BGP best practices (RFC 4451).
4. Recommendation: Configure 'set metric igp-cost' in BGP route-maps to ensure MED matches IGP metric. If using iBGP with next-hop-self, verify the IGP metric to the advertising router, not the original next-hop. Audit all route-maps for static MED values. Consider using 'bgp bestpath med missing-as-worst' for consistent behavior.
</reasoning>
<answer>
WARNING: BGP MED/IGP metric inconsistency for 10.35.214.0/24. MED 1220 does not match IGP metric 41 to next-hop 192.168.82.53. Check route-map MED configuration and IGP correlation. MED should reflect true internal cost per RFC 4451.
</answer>


[System] You are a network routing expert. Analyze the routing table, detect issues, and provide step-by-step reasoning. Use the format: <reasoning>...step-by-step analysis...</reasoning><answer>...concise answer...</answer>

[User]
Routing table:
O    10.140.255.0/27 [110/5] via 192.168.55.26, 22:58:47, Loopback67
D    10.247.33.0/20 [90/639] via 192.168.51.87
D    10.38.35.0/24 [90/396891] via 192.168.34.242
D    10.44.84.0/29 [90/852] via 192.168.244.41
O    10.26.61.0/20 [110/11] via 192.168.98.41, 04:22:11, Loopback20
D    10.88.99.0/21 [90/779] via 192.168.205.150
O    10.216.183.0/29 [110/10] via 192.168.109.86, 03:59:52, Loopback13
O    10.38.35.0/24 [110/10] via 192.168.240.119, 15:44:10, FastEthernet0/2
L    192.168.1.1/32 is directly connected, GigabitEthernet0/0
D    10.53.55.0/26 [90/525] via 192.168.149.154
O    10.189.211.0/18 [110/14] via 192.168.174.54, 14:47:13, Loopback12
C    192.168.1.0/24 is directly connected, GigabitEthernet0/0

Question: Analyze this routing table for Administrative Distance conflicts.

[Assistant]
<reasoning>
1. Observation: Network 10.38.35.0/24 appears in both OSPF (metric 10, AD 110) and EIGRP (metric 396891, AD 90). The metrics differ by 39689x, but EIGRP's lower AD (90 < 110) makes it the active route.
2. Analysis: OSPF and EIGRP use completely different metric scales. OSPF cost is based on cumulative link bandwidth (typically 1–65535), while EIGRP composite metric combines bandwidth, delay, load, and reliability (typically 100–10,000,000). Direct comparison is meaningless. However, the coexistence of both protocols for the same prefix indicates route redistribution or accidental dual-protocol deployment.
3. Context: If redistribution is intentional, metrics must be scaled appropriately (e.g., OSPF→EIGRP metric translation). If accidental, the protocols compete for RIB installation, causing route flapping if AD values are manipulated. The EIGRP path may be suboptimal despite lower AD if the OSPF path is actually better in terms of latency/hops.
4. Recommendation: Verify if dual-protocol learning is intentional. If redistributing, use route-maps with metric scaling (e.g., 'set metric 10000 100 255 1 1500' for EIGRP). If accidental, remove one protocol from the interface or use distribute-lists. Ensure AD values reflect true path preference—consider 'distance eigrp' or 'distance ospf' adjustments.
</reasoning>
<answer>
WARNING: Inconsistent metrics between protocols for 10.38.35.0/24. OSPF metric 10 vs EIGRP metric 396891 (different scales). EIGRP wins due to lower AD (90). Verify redistribution scaling or remove accidental dual-protocol deployment.
</answer>


[System] You are a network routing expert. Analyze the routing table, detect issues, and provide step-by-step reasoning. Use the format: <reasoning>...step-by-step analysis...</reasoning><answer>...concise answer...</answer>

[User]
Routing table:
O    10.140.136.0/18 [110/15] via 192.168.122.91, 12:31:35, FastEthernet1/0
B    10.27.40.0/27 [20/4] via 192.168.37.173
B    10.51.131.0/28 [20/46] via 192.168.231.119
O    10.158.222.0/27 [110/13] via 192.168.223.82, 08:33:23, Serial3/1:0
B    10.129.58.0/25 [20/18] via 192.168.116.13
O    10.235.181.0/19 [110/14] via 192.168.226.27, 13:41:48, Serial0/1:0
O    10.104.113.0/18 [110/16] via 192.168.132.121, 10:08:54, GigabitEthernet3/3
L    192.168.1.1/32 is directly connected, GigabitEthernet0/0
B    10.176.125.0/29 [20/39] via 192.168.237.83
B    10.87.242.0/30 [20/42] via 192.168.28.10
C    192.168.1.0/24 is directly connected, GigabitEthernet0/0
O    10.23.220.0/17 [110/16] via 192.168.13.99, 19:39:39, Port-channel1
O    192.168.179.0/24 [110/12] via 192.168.60.156, 01:11:47, Loopback89
B    10.18.30.0/17 [20/49] via 192.168.184.185
B    10.2.217.0/24 [20/558] via 192.168.179.83

Question: Identify all potential issues in this routing table and classify them by severity.

[Assistant]
<reasoning>
1. Observation: BGP route to 10.2.217.0/24 has MED 558, but the IGP (OSPF) metric to its next-hop 192.168.179.83 is only 12. The MED is 46x to 558x higher than the actual IGP cost.
2. Analysis: MED should ideally reflect the IGP metric from the advertising router to the BGP next-hop. A large discrepancy indicates: (a) MED is manually set without IGP correlation, (b) IGP metric changed after BGP advertisement, (c) redistribution from another protocol with different metric scale, or (d) route-map setting MED based on a static value rather than dynamic IGP.
3. Context: Inconsistent MED-to-IGP mapping breaks hot-potato routing. Traffic may enter the AS at a suboptimal point because MED doesn't reflect true internal cost. This causes inefficient inter-domain traffic patterns and violates BGP best practices (RFC 4451).
4. Recommendation: Configure 'set metric igp-cost' in BGP route-maps to ensure MED matches IGP metric. If using iBGP with next-hop-self, verify the IGP metric to the advertising router, not the original next-hop. Audit all route-maps for static MED values. Consider using 'bgp bestpath med missing-as-worst' for consistent behavior.
</reasoning>
<answer>
WARNING: BGP MED/IGP metric inconsistency for 10.2.217.0/24. MED 558 does not match IGP metric 12 to next-hop 192.168.179.83. Check route-map MED configuration and IGP correlation. MED should reflect true internal cost per RFC 4451.
</answer>


[System] You are a network routing expert. Analyze the routing table, detect issues, and provide step-by-step reasoning. Use the format: <reasoning>...step-by-step analysis...</reasoning><answer>...concise answer...</answer>

[User]
Routing table:
D    10.180.96.0/27 [90/384] via 192.168.93.244
D    10.29.175.0/24 [90/262120] via 192.168.111.161
L    192.168.1.1/32 is directly connected, GigabitEthernet0/0
D    10.128.106.0/16 [90/947] via 192.168.27.58
O    10.29.175.0/24 [110/5] via 192.168.2.219, 02:11:14, Port-channel7
D    10.210.153.0/20 [90/561] via 192.168.33.198
C    192.168.1.0/24 is directly connected, GigabitEthernet0/0
O    10.9.116.0/19 [110/19] via 192.168.86.229, 17:05:21, Port-channel7
O    10.18.15.0/21 [110/7] via 192.168.24.144, 03:30:18, GigabitEthernet2/2
D    10.85.199.0/20 [90/172] via 192.168.87.24
O    10.96.0.0/24 [110/20] via 192.168.181.55, 12:58:08, Serial3/0:0
D    10.14.65.0/24 [90/281] via 192.168.149.15
O    10.222.174.0/29 [110/20] via 192.168.125.49, 11:42:22, Port-channel5
D    10.255.125.0/28 [90/453] via 192.168.218.126

Question: Analyze this routing table for Administrative Distance conflicts.

[Assistant]
<reasoning>
1. Observation: Network 10.29.175.0/24 appears in both OSPF (metric 5, AD 110) and EIGRP (metric 262120, AD 90). The metrics differ by 52424x, but EIGRP's lower AD (90 < 110) makes it the active route.
2. Analysis: OSPF and EIGRP use completely different metric scales. OSPF cost is based on cumulative link bandwidth (typically 1–65535), while EIGRP composite metric combines bandwidth, delay, load, and reliability (typically 100–10,000,000). Direct comparison is meaningless. However, the coexistence of both protocols for the same prefix indicates route redistribution or accidental dual-protocol deployment.
3. Context: If redistribution is intentional, metrics must be scaled appropriately (e.g., OSPF→EIGRP metric translation). If accidental, the protocols compete for RIB installation, causing route flapping if AD values are manipulated. The EIGRP path may be suboptimal despite lower AD if the OSPF path is actually better in terms of latency/hops.
4. Recommendation: Verify if dual-protocol learning is intentional. If redistributing, use route-maps with metric scaling (e.g., 'set metric 10000 100 255 1 1500' for EIGRP). If accidental, remove one protocol from the interface or use distribute-lists. Ensure AD values reflect true path preference—consider 'distance eigrp' or 'distance ospf' adjustments.
</reasoning>
<answer>
WARNING: Inconsistent metrics between protocols for 10.29.175.0/24. OSPF metric 5 vs EIGRP metric 262120 (different scales). EIGRP wins due to lower AD (90). Verify redistribution scaling or remove accidental dual-protocol deployment.
</answer>


[System] You are a network routing expert. Analyze the routing table, detect issues, and provide step-by-step reasoning. Use the format: <reasoning>...step-by-step analysis...</reasoning><answer>...concise answer...</answer>

[User]
Routing table:
B    10.5.219.0/24 [20/1057] via 192.168.50.146
B    10.95.226.0/25 [20/6] via 192.168.236.54
B    10.159.15.0/23 [20/11] via 192.168.82.106
B    10.15.107.0/28 [20/14] via 192.168.241.145
B    10.37.193.0/25 [20/3] via 192.168.247.196
B    10.183.18.0/20 [20/15] via 192.168.110.153
B    10.81.191.0/21 [20/10] via 192.168.165.186
B    10.183.5.0/16 [20/3] via 192.168.129.115
B    10.71.30.0/26 [20/6] via 192.168.89.100
L    192.168.1.1/32 is directly connected, GigabitEthernet0/0
B    10.148.192.0/30 [20/9] via 192.168.82.35
B    10.65.212.0/29 [20/1] via 192.168.20.14
B    10.245.179.0/17 [20/7] via 192.168.95.227
C    192.168.1.0/24 is directly connected, GigabitEthernet0/0
B    10.219.166.0/17 [20/7] via 192.168.225.80
B    10.228.218.0/22 [20/7] via 192.168.218.157

Question: Analyze this routing table for Administrative Distance conflicts.

[Assistant]
<reasoning>
1. Observation: BGP route to 10.5.219.0/24 has MED 1057, while all other BGP routes have MED between 0 and 15. The MED deviation is 70x to 1057x from the normal range.
2. Analysis: MED (Multi-Exit Discriminator) is used for inter-AS path selection when multiple paths exist from the same neighboring AS. A MED of 1057 is atypical—normal MED values reflect IGP cost (usually <1000). This extreme value suggests: (a) IGP metric redistribution without scaling, (b) manual MED policy misconfiguration, (c) AS-path prepending combined with MED, or (d) a BGP community setting MED incorrectly.
3. Context: BGP best-path selection compares MED after weight, local-preference, and AS-path length. An extreme MED makes this path the least preferred among equal AS-path alternatives, effectively black-holing traffic if it's the only path. It also complicates traffic engineering.
4. Recommendation: Verify MED configuration on the advertising router. Check route-maps setting MED based on IGP metric—consider dividing by a factor (e.g., 'set metric igp-cost / 10'). Review BGP communities that manipulate MED. Ensure consistent MED policy across all BGP speakers in the AS.
</reasoning>
<answer>
WARNING: BGP MED skew for 10.5.219.0/24. MED 1057 is 70x–1057x higher than normal (0–15). Check IGP redistribution scaling, route-map MED policies, and community configurations. Path likely depreferred.
</answer>


[System] You are a network routing expert. Analyze the routing table, detect issues, and provide step-by-step reasoning. Use the format: <reasoning>...step-by-step analysis...</reasoning><answer>...concise answer...</answer>

[User]
Routing table:
O    10.19.2.0/24 [110/1222] via 192.168.65.148, 23:04:32, Serial2/1:1
O    10.217.210.0/18 [110/19] via 192.168.53.172, 14:52:06, Serial2/1:0
O    10.193.70.0/25 [110/15] via 192.168.181.62, 20:26:32, FastEthernet1/3
L    192.168.1.1/32 is directly connected, GigabitEthernet0/0
O    10.28.34.0/27 [110/2] via 192.168.249.167, 02:59:16, FastEthernet3/1
O    10.201.101.0/22 [110/8] via 192.168.244.81, 14:05:09, Loopback86
O    10.21.145.0/27 [110/17] via 192.168.51.7, 22:01:50, Serial0/1:1
O    10.44.1.0/24 [110/10] via 192.168.31.104, 15:18:43, Serial2/1:1
O    10.21.97.0/21 [110/14] via 192.168.146.224, 21:02:25, Port-channel3
O    10.141.247.0/29 [110/10] via 192.168.70.62, 22:06:24, Port-channel2
C    192.168.1.0/24 is directly connected, GigabitEthernet0/0
O    10.32.102.0/20 [110/5] via 192.168.153.108, 20:10:28, GigabitEthernet1/1
O    10.124.138.0/16 [110/13] via 192.168.32.42, 10:35:02, Port-channel8
O    10.46.13.0/28 [110/10] via 192.168.142.218, 17:18:15, FastEthernet3/3

Question: Does this routing table have any routing inconsistencies?

[Assistant]
<reasoning>
1. Observation: Intra-area route 10.44.1.0/24 has metric 10, while inter-area route 10.19.2.0/24 has metric 1222. The inter-area metric is 1212 higher despite both destinations being roughly equidistant.
2. Analysis: OSPF inter-area routes are calculated as the sum of intra-area cost to the ABR plus the cost from ABR to destination. An abnormally high inter-area metric suggests: (a) suboptimal ABR placement, (b) a high-cost link in the backbone (Area 0), (c) virtual link with accumulated cost, or (d) summary LSA (Type 3) advertising a high metric from the ABR.
3. Context: Inter-area metric inconsistency causes suboptimal routing—traffic to 10.19.2.0/24 takes a much longer path than necessary. This can create asymmetric routing if return traffic takes a shorter intra-area path. It also complicates traffic engineering and SLA compliance.
4. Recommendation: Verify ABR placement and backbone topology. Check 'show ip ospf database summary' for the advertised metric of 10.19.2.0/24. Ensure virtual links (if used) are not adding excessive cost. Consider using 'area range' with 'cost' override on ABRs to normalize inter-area metrics. Verify all backbone links have consistent bandwidth settings.
</reasoning>
<answer>
WARNING: OSPF inter-area metric inconsistency. 10.19.2.0/24 metric 1222 is 1212 higher than intra-area 10.44.1.0/24 (10). Check ABR placement, backbone link costs, virtual links, and summary LSA metrics. Suboptimal routing likely.
</answer>


[System] You are a network routing expert. Analyze the routing table, detect issues, and provide step-by-step reasoning. Use the format: <reasoning>...step-by-step analysis...</reasoning><answer>...concise answer...</answer>

[User]
Routing table:
O    10.166.1.0/21 [110/10] via 192.168.132.57, 03:48:11, Serial1/1:0
O    10.9.85.0/24 [110/133] via 192.168.108.5, 00:00:25, FastEthernet0/1
O    10.219.191.0/26 [110/10] via 192.168.126.100, 09:33:33, Loopback6
O    10.151.142.0/21 [110/8] via 192.168.202.88, 20:47:47, FastEthernet1/1
O    10.121.14.0/24 [110/15] via 192.168.158.26, 05:00:28, Serial2/0:0
O    10.15.76.0/27 [110/7] via 192.168.89.201, 10:56:26, FastEthernet1/2
C    192.168.1.0/24 is directly connected, GigabitEthernet0/0
O    10.3.58.0/27 [110/5] via 192.168.154.166, 05:44:05, FastEthernet2/1
O    10.9.85.0/24 [110/10] via 192.168.27.118, 00:00:06, Serial3/1:0
L    192.168.1.1/32 is directly connected, GigabitEthernet0/0
O    10.82.112.0/23 [110/18] via 192.168.243.77, 05:32:09, Serial0/0:0
O    10.174.167.0/26 [110/20] via 192.168.139.114, 08:15:13, GigabitEthernet2/2

Question: Does this routing table have any routing inconsistencies?

[Assistant]
<reasoning>
1. Observation: Two OSPF routes to 10.9.85.0/24 exist with different metrics: 10 via 192.168.27.118 (recent) and 133 via 192.168.108.5 (more recent). The metric oscillated by 123 within 30 seconds.
2. Analysis: Metric flapping in OSPF indicates interface cost instability. Possible causes: (a) interface bandwidth auto-negotiation flapping between speeds (e.g., 1Gbps ↔ 100Mbps), (b) reference bandwidth change on an upstream router, (c) LSA refresh from a router with inconsistent cost, or (d) a link with intermittent congestion causing OSPF to recalculate.
3. Context: Metric flapping triggers repeated SPF calculations, consuming CPU. It also causes route churn in the RIB and FIB, leading to packet loss and out-of-order delivery. CEF may alternate between next-hops, causing micro-looping.
4. Recommendation: Check interface speed/duplex on all links toward 10.9.85.0/24 with 'show interface'. Verify 'auto-cost reference-bandwidth' is identical on all routers in the area. Check for LSA Type 1/2 flooding storms. Consider enabling OSPF SPF throttling ('timers throttle spf') to dampen recalculation frequency.
</reasoning>
<answer>
WARNING: OSPF metric flapping for 10.9.85.0/24. Metric oscillated between 10 and 133 within 30 seconds. Check interface speed/duplex negotiation, reference-bandwidth consistency, and LSA flooding. Enable SPF throttling to reduce CPU impact.
</answer>


[System] You are a network routing expert. Analyze the routing table, detect issues, and provide step-by-step reasoning. Use the format: <reasoning>...step-by-step analysis...</reasoning><answer>...concise answer...</answer>

[User]
Routing table:
D    10.12.186.0/16 [90/998] via 192.168.195.16
C    192.168.1.0/24 is directly connected, GigabitEthernet0/0
D    10.119.118.0/27 [90/986] via 192.168.73.88
D    10.61.230.0/16 [90/420] via 192.168.152.32
D    10.20.79.0/24 [90/7296060] via 192.168.79.7
L    192.168.1.1/32 is directly connected, GigabitEthernet0/0
D    10.46.70.0/20 [90/450] via 192.168.60.117
D    10.12.89.0/16 [90/469] via 192.168.68.181
D    10.75.162.0/25 [90/230] via 192.168.237.51
D    10.61.236.0/30 [90/207] via 192.168.27.211
D    10.82.192.0/20 [90/483] via 192.168.114.209
D    10.69.206.0/18 [90/578] via 192.168.114.242
D    10.208.202.0/28 [90/187] via 192.168.77.133
D    10.168.49.0/22 [90/365] via 192.168.255.107

Question: Does this routing table have any routing inconsistencies?

[Assistant]
<reasoning>
1. Observation: EIGRP route to 10.20.79.0/24 has composite metric 7296060, while other EIGRP routes have metrics between 100 and 1000. The deviation is 7296x to 72960x from normal.
2. Analysis: EIGRP composite metric = (K1 * bandwidth + K2 * bandwidth/(256-load) + K3 * delay) * K5/(reliability + K4). A metric of 7296060 indicates either: (a) a very low-bandwidth link (e.g., T1 at 1544 kbps with high delay), (b) a satellite or MPLS link with high delay, (c) interface bandwidth misconfigured to 1 kbps, or (d) K-values mismatch between neighbors causing metric calculation divergence.
3. Context: EIGRP uses the composite metric for best-path and feasible successor selection. An abnormally high metric may prevent the route from being used even when it's the only path, or cause feasible successor rejection. The route may also indicate a SIA condition if the metric keeps increasing.
4. Recommendation: Verify 'bandwidth' and 'delay' interface parameters on all links toward 10.20.79.0/24. Check K-value consistency with 'show ip eigrp neighbors' and 'show ip protocols'. If the path includes a satellite/WAN link, consider adjusting delay to reflect actual latency. Verify no interface bandwidth is set to 1 kbps accidentally.
</reasoning>
<answer>
WARNING: Severe EIGRP metric skew for 10.20.79.0/24. Composite metric 7296060 is 7296x–72960x higher than normal (100–1000). Check interface bandwidth/delay, K-values consistency, and SIA conditions.
</answer>


[System] You are a network routing expert. Analyze the routing table, detect issues, and provide step-by-step reasoning. Use the format: <reasoning>...step-by-step analysis...</reasoning><answer>...concise answer...</answer>

[User]
Routing table:
D    10.164.55.0/26 [90/917] via 192.168.41.230
D    10.30.13.0/24 [90/301014] via 192.168.11.79
D    10.251.196.0/17 [90/873] via 192.168.147.42
O    10.184.49.0/16 [110/17] via 192.168.200.73, 01:53:05, Port-channel5
O    10.129.104.0/18 [110/13] via 192.168.216.188, 10:46:33, Port-channel6
D    10.227.107.0/20 [90/415] via 192.168.64.124
D    10.178.154.0/21 [90/255] via 192.168.242.166
D    10.239.125.0/29 [90/867] via 192.168.165.251
L    192.168.1.1/32 is directly connected, GigabitEthernet0/0
O    10.174.161.0/26 [110/5] via 192.168.28.103, 02:57:16, GigabitEthernet2/2
O    10.30.13.0/24 [110/15] via 192.168.211.200, 19:27:31, GigabitEthernet2/3
O    10.138.0.0/30 [110/9] via 192.168.229.175, 14:36:51, Loopback19
O    10.103.15.0/22 [110/19] via 192.168.67.197, 18:39:05, GigabitEthernet0/3
C    192.168.1.0/24 is directly connected, GigabitEthernet0/0

Question: Analyze this routing table for Administrative Distance conflicts.

[Assistant]
<reasoning>
1. Observation: Network 10.30.13.0/24 appears in both OSPF (metric 15, AD 110) and EIGRP (metric 301014, AD 90). The metrics differ by 20067x, but EIGRP's lower AD (90 < 110) makes it the active route.
2. Analysis: OSPF and EIGRP use completely different metric scales. OSPF cost is based on cumulative link bandwidth (typically 1–65535), while EIGRP composite metric combines bandwidth, delay, load, and reliability (typically 100–10,000,000). Direct comparison is meaningless. However, the coexistence of both protocols for the same prefix indicates route redistribution or accidental dual-protocol deployment.
3. Context: If redistribution is intentional, metrics must be scaled appropriately (e.g., OSPF→EIGRP metric translation). If accidental, the protocols compete for RIB installation, causing route flapping if AD values are manipulated. The EIGRP path may be suboptimal despite lower AD if the OSPF path is actually better in terms of latency/hops.
4. Recommendation: Verify if dual-protocol learning is intentional. If redistributing, use route-maps with metric scaling (e.g., 'set metric 10000 100 255 1 1500' for EIGRP). If accidental, remove one protocol from the interface or use distribute-lists. Ensure AD values reflect true path preference—consider 'distance eigrp' or 'distance ospf' adjustments.
</reasoning>
<answer>
WARNING: Inconsistent metrics between protocols for 10.30.13.0/24. OSPF metric 15 vs EIGRP metric 301014 (different scales). EIGRP wins due to lower AD (90). Verify redistribution scaling or remove accidental dual-protocol deployment.
</answer>


[System] You are a network routing expert. Analyze the routing table, detect issues, and provide step-by-step reasoning. Use the format: <reasoning>...step-by-step analysis...</reasoning><answer>...concise answer...</answer>

[User]
Routing table:
B    10.25.3.0/24 [20/171] via 192.168.73.76
B    10.25.3.0/24 [20/2] via 192.168.27.16
B    10.60.219.0/21 [20/8] via 192.168.65.108
B    10.237.135.0/19 [20/7] via 192.168.133.135
B    10.52.136.0/21 [20/6] via 192.168.247.123
B    10.20.245.0/19 [20/2] via 192.168.18.182
B    10.245.62.0/20 [20/6] via 192.168.148.21
C    192.168.1.0/24 is directly connected, GigabitEthernet0/0
L    192.168.1.1/32 is directly connected, GigabitEthernet0/0
B    10.133.168.0/20 [20/8] via 192.168.18.120
B    10.72.253.0/24 [20/2] via 192.168.162.215
B    10.107.78.0/29 [20/8] via 192.168.108.234
B    10.12.180.0/29 [20/1] via 192.168.92.126

Question: Identify all potential issues in this routing table and classify them by severity.

[Assistant]
<reasoning>
1. Observation: Two BGP routes to 10.25.3.0/24 exist with oscillating MED values: 2 via 192.168.27.16 and 171 via 192.168.73.76. The MED difference of 169 causes repeated best-path changes.
2. Analysis: MED flapping between BGP peers indicates inconsistent IGP metric redistribution. Possible causes: (a) IGP metric changes on the path to the next-hop, (b) route-map applying MED based on a dynamic metric (e.g., delay, load), (c) dual-homed peers with different IGP costs, or (d) BGP policy oscillation between two route-maps.
3. Context: BGP best-path selection runs for each prefix when MED changes. With many prefixes, this causes CPU spikes and route churn. The router may also send repeated updates to downstream peers, amplifying the instability. MED oscillation is a known cause of BGP route dampening activation.
4. Recommendation: Stabilize the IGP metric to the BGP next-hop addresses. Use 'set metric' with a fixed value in route-maps instead of dynamic IGP-derived MED. Consider using 'bgp deterministic-med' to ensure consistent comparison. Implement BGP route dampening to suppress flapping prefixes. If using IGP-derived MED, ensure IGP is stable (e.g., OSPF cost not flapping).
</reasoning>
<answer>
WARNING: BGP MED flapping for 10.25.3.0/24. MED oscillates between 2 and 171. Check IGP metric stability, route-map MED policies, and 'bgp deterministic-med'. Implement BGP dampening. CPU impact from repeated best-path selection.
</answer>


[System] You are a network routing expert. Analyze the routing table, detect issues, and provide step-by-step reasoning. Use the format: <reasoning>...step-by-step analysis...</reasoning><answer>...concise answer...</answer>

[User]
Routing table:
B    10.11.222.0/24 [20/1065] via 192.168.211.103
B    10.189.106.0/25 [20/48] via 192.168.87.30
O    10.227.198.0/20 [110/12] via 192.168.206.216, 22:57:12, Serial2/0:0
O    192.168.211.0/24 [110/36] via 192.168.135.103, 06:42:09, FastEthernet2/2
O    10.127.185.0/28 [110/17] via 192.168.100.129, 06:34:17, Loopback84
O    10.20.237.0/20 [110/14] via 192.168.210.222, 08:22:40, Port-channel1
C    192.168.1.0/24 is directly connected, GigabitEthernet0/0
B    10.228.126.0/26 [20/43] via 192.168.62.115
O    10.162.252.0/19 [110/11] via 192.168.200.13, 08:43:31, Serial2/0:0
B    10.251.117.0/25 [20/20] via 192.168.42.159
L    192.168.1.1/32 is directly connected, GigabitEthernet0/0
B    10.243.156.0/19 [20/28] via 192.168.185.56
O    10.204.18.0/19 [110/11] via 192.168.246.157, 00:37:05, FastEthernet2/2
O    10.54.231.0/20 [110/5] via 192.168.140.158, 12:04:46, FastEthernet2/2
B    10.54.214.0/18 [20/40] via 192.168.40.138

Question: Identify all potential issues in this routing table and classify them by severity.

[Assistant]
<reasoning>
1. Observation: BGP route to 10.11.222.0/24 has MED 1065, but the IGP (OSPF) metric to its next-hop 192.168.211.103 is only 36. The MED is 29x to 1065x higher than the actual IGP cost.
2. Analysis: MED should ideally reflect the IGP metric from the advertising router to the BGP next-hop. A large discrepancy indicates: (a) MED is manually set without IGP correlation, (b) IGP metric changed after BGP advertisement, (c) redistribution from another protocol with different metric scale, or (d) route-map setting MED based on a static value rather than dynamic IGP.
3. Context: Inconsistent MED-to-IGP mapping breaks hot-potato routing. Traffic may enter the AS at a suboptimal point because MED doesn't reflect true internal cost. This causes inefficient inter-domain traffic patterns and violates BGP best practices (RFC 4451).
4. Recommendation: Configure 'set metric igp-cost' in BGP route-maps to ensure MED matches IGP metric. If using iBGP with next-hop-self, verify the IGP metric to the advertising router, not the original next-hop. Audit all route-maps for static MED values. Consider using 'bgp bestpath med missing-as-worst' for consistent behavior.
</reasoning>
<answer>
WARNING: BGP MED/IGP metric inconsistency for 10.11.222.0/24. MED 1065 does not match IGP metric 36 to next-hop 192.168.211.103. Check route-map MED configuration and IGP correlation. MED should reflect true internal cost per RFC 4451.
</answer>


[System] You are a network routing expert. Analyze the routing table, detect issues, and provide step-by-step reasoning. Use the format: <reasoning>...step-by-step analysis...</reasoning><answer>...concise answer...</answer>

[User]
Routing table:
D    10.192.117.0/27 [90/157] via 192.168.49.253
D    10.193.79.0/30 [90/268] via 192.168.133.105
D    10.119.115.0/24 [90/409] via 192.168.249.249
D    10.227.247.0/27 [90/165] via 192.168.241.235
D    10.87.180.0/27 [90/946] via 192.168.227.62
D    10.176.67.0/18 [90/341] via 192.168.6.229
L    192.168.1.1/32 is directly connected, GigabitEthernet0/0
D    10.30.54.0/24 [90/4450] via 192.168.62.164
D    10.172.126.0/20 [90/236] via 192.168.172.220
D    10.186.180.0/26 [90/465] via 192.168.50.38
D    10.192.3.0/23 [90/914] via 192.168.102.216
D    10.178.153.0/29 [90/249] via 192.168.95.23
D    10.131.78.0/16 [90/119] via 192.168.202.44
C    192.168.1.0/24 is directly connected, GigabitEthernet0/0

Question: What routing issues could cause network instability in this configuration?

[Assistant]
<reasoning>
1. Observation: EIGRP route to 10.30.54.0/24 has metric 4450, which is 655 higher than the expected baseline of 3795. Topology table shows repeated metric increases over the last 5 minutes.
2. Analysis: EIGRP metric increases indicate deteriorating path quality. Possible causes: (a) increasing interface delay due to queue buildup or congestion, (b) bandwidth reduction from auto-negotiation downgrading, (c) a new link with worse characteristics being added to the path, or (d) K-value changes causing recalculation.
3. Context: Unlike OSPF, EIGRP metrics are dynamic and reflect real-time path quality. A steadily increasing metric suggests the path is degrading. If the metric exceeds the feasible distance of the successor, EIGRP will query for a new path, potentially causing SIA if no feasible successor exists.
4. Recommendation: Monitor interface counters on all links toward 10.30.54.0/24 for errors, drops, or queue saturation. Check 'show interface' for bandwidth and delay changes. Verify K-values are consistent across all EIGRP neighbors. If the path includes a WAN link, check SLA metrics and provider circuit health. Consider implementing EIGRP stub to limit query scope.
</reasoning>
<answer>
WARNING: EIGRP metric flapping/increasing for 10.30.54.0/24. Metric rose from 3795 to 4450. Check interface delay/bandwidth, queue congestion, K-values consistency, and WAN link health. SIA risk if no feasible successor.
</answer>


[System] You are a network routing expert. Analyze the routing table, detect issues, and provide step-by-step reasoning. Use the format: <reasoning>...step-by-step analysis...</reasoning><answer>...concise answer...</answer>

[User]
Routing table:
B    10.27.23.0/17 [20/18] via 192.168.133.163
O    10.143.3.0/23 [110/10] via 192.168.211.173, 12:51:44, Loopback65
B    10.246.62.0/18 [20/3] via 192.168.236.64
O    10.54.219.0/20 [110/2] via 192.168.56.66, 14:53:19, GigabitEthernet0/2
C    192.168.1.0/24 is directly connected, GigabitEthernet0/0
O    192.168.15.0/24 [110/24] via 192.168.4.181, 22:19:25, Loopback0
O    10.56.172.0/26 [110/11] via 192.168.84.173, 13:19:39, GigabitEthernet3/2
O    10.247.129.0/22 [110/10] via 192.168.253.58, 16:11:21, FastEthernet1/3
B    10.5.46.0/24 [20/925] via 192.168.15.78
L    192.168.1.1/32 is directly connected, GigabitEthernet0/0
B    10.30.203.0/22 [20/30] via 192.168.75.222
O    10.98.40.0/26 [110/2] via 192.168.182.225, 22:56:42, Port-channel6
O    10.91.54.0/30 [110/13] via 192.168.27.67, 16:14:48, Serial1/1:0

Question: Identify all potential issues in this routing table and classify them by severity.

[Assistant]
<reasoning>
1. Observation: BGP route to 10.5.46.0/24 has MED 925, but the IGP (OSPF) metric to its next-hop 192.168.15.78 is only 24. The MED is 38x to 925x higher than the actual IGP cost.
2. Analysis: MED should ideally reflect the IGP metric from the advertising router to the BGP next-hop. A large discrepancy indicates: (a) MED is manually set without IGP correlation, (b) IGP metric changed after BGP advertisement, (c) redistribution from another protocol with different metric scale, or (d) route-map setting MED based on a static value rather than dynamic IGP.
3. Context: Inconsistent MED-to-IGP mapping breaks hot-potato routing. Traffic may enter the AS at a suboptimal point because MED doesn't reflect true internal cost. This causes inefficient inter-domain traffic patterns and violates BGP best practices (RFC 4451).
4. Recommendation: Configure 'set metric igp-cost' in BGP route-maps to ensure MED matches IGP metric. If using iBGP with next-hop-self, verify the IGP metric to the advertising router, not the original next-hop. Audit all route-maps for static MED values. Consider using 'bgp bestpath med missing-as-worst' for consistent behavior.
</reasoning>
<answer>
WARNING: BGP MED/IGP metric inconsistency for 10.5.46.0/24. MED 925 does not match IGP metric 24 to next-hop 192.168.15.78. Check route-map MED configuration and IGP correlation. MED should reflect true internal cost per RFC 4451.
</answer>


[System] You are a network routing expert. Analyze the routing table, detect issues, and provide step-by-step reasoning. Use the format: <reasoning>...step-by-step analysis...</reasoning><answer>...concise answer...</answer>

[User]
Routing table:
B    10.189.11.0/20 [20/4] via 192.168.197.83
B    10.242.246.0/17 [20/7] via 192.168.254.248
B    10.46.110.0/26 [20/5] via 192.168.69.231
B    10.181.71.0/17 [20/13] via 192.168.87.198
B    10.15.189.0/24 [20/343] via 192.168.125.171
B    10.252.178.0/28 [20/8] via 192.168.37.249
C    192.168.1.0/24 is directly connected, GigabitEthernet0/0
B    10.2.214.0/18 [20/6] via 192.168.162.80
L    192.168.1.1/32 is directly connected, GigabitEthernet0/0
B    10.46.114.0/28 [20/0] via 192.168.21.79
B    10.64.43.0/17 [20/5] via 192.168.2.247
B    10.194.57.0/23 [20/14] via 192.168.239.108
B    10.45.65.0/29 [20/1] via 192.168.192.82
B    10.239.118.0/19 [20/0] via 192.168.221.213
B    10.15.189.0/24 [20/4] via 192.168.232.56
B    10.107.0.0/25 [20/0] via 192.168.117.217

Question: Identify all potential issues in this routing table and classify them by severity.

[Assistant]
<reasoning>
1. Observation: Two BGP routes to 10.15.189.0/24 exist with oscillating MED values: 4 via 192.168.232.56 and 343 via 192.168.125.171. The MED difference of 339 causes repeated best-path changes.
2. Analysis: MED flapping between BGP peers indicates inconsistent IGP metric redistribution. Possible causes: (a) IGP metric changes on the path to the next-hop, (b) route-map applying MED based on a dynamic metric (e.g., delay, load), (c) dual-homed peers with different IGP costs, or (d) BGP policy oscillation between two route-maps.
3. Context: BGP best-path selection runs for each prefix when MED changes. With many prefixes, this causes CPU spikes and route churn. The router may also send repeated updates to downstream peers, amplifying the instability. MED oscillation is a known cause of BGP route dampening activation.
4. Recommendation: Stabilize the IGP metric to the BGP next-hop addresses. Use 'set metric' with a fixed value in route-maps instead of dynamic IGP-derived MED. Consider using 'bgp deterministic-med' to ensure consistent comparison. Implement BGP route dampening to suppress flapping prefixes. If using IGP-derived MED, ensure IGP is stable (e.g., OSPF cost not flapping).
</reasoning>
<answer>
WARNING: BGP MED flapping for 10.15.189.0/24. MED oscillates between 4 and 343. Check IGP metric stability, route-map MED policies, and 'bgp deterministic-med'. Implement BGP dampening. CPU impact from repeated best-path selection.
</answer>


[System] You are a network routing expert. Analyze the routing table, detect issues, and provide step-by-step reasoning. Use the format: <reasoning>...step-by-step analysis...</reasoning><answer>...concise answer...</answer>

[User]
Routing table:
B    10.198.213.0/22 [20/13] via 192.168.116.201
B    10.206.61.0/30 [20/0] via 192.168.118.47
B    10.189.42.0/22 [20/9] via 192.168.246.123
B    10.154.241.0/20 [20/7] via 192.168.59.214
B    10.209.119.0/19 [20/0] via 192.168.223.88
B    10.18.183.0/24 [20/12] via 192.168.92.250
B    10.105.32.0/21 [20/6] via 192.168.134.201
B    10.137.197.0/28 [20/1] via 192.168.16.124
B    10.65.111.0/23 [20/6] via 192.168.151.240
B    10.30.206.0/24 [20/137] via 192.168.106.124
L    192.168.1.1/32 is directly connected, GigabitEthernet0/0
B    10.30.206.0/24 [20/2] via 192.168.157.47
C    192.168.1.0/24 is directly connected, GigabitEthernet0/0
B    10.227.221.0/20 [20/3] via 192.168.53.115

Question: Identify all potential issues in this routing table and classify them by severity.

[Assistant]
<reasoning>
1. Observation: Two BGP routes to 10.30.206.0/24 exist with oscillating MED values: 2 via 192.168.157.47 and 137 via 192.168.106.124. The MED difference of 135 causes repeated best-path changes.
2. Analysis: MED flapping between BGP peers indicates inconsistent IGP metric redistribution. Possible causes: (a) IGP metric changes on the path to the next-hop, (b) route-map applying MED based on a dynamic metric (e.g., delay, load), (c) dual-homed peers with different IGP costs, or (d) BGP policy oscillation between two route-maps.
3. Context: BGP best-path selection runs for each prefix when MED changes. With many prefixes, this causes CPU spikes and route churn. The router may also send repeated updates to downstream peers, amplifying the instability. MED oscillation is a known cause of BGP route dampening activation.
4. Recommendation: Stabilize the IGP metric to the BGP next-hop addresses. Use 'set metric' with a fixed value in route-maps instead of dynamic IGP-derived MED. Consider using 'bgp deterministic-med' to ensure consistent comparison. Implement BGP route dampening to suppress flapping prefixes. If using IGP-derived MED, ensure IGP is stable (e.g., OSPF cost not flapping).
</reasoning>
<answer>
WARNING: BGP MED flapping for 10.30.206.0/24. MED oscillates between 2 and 137. Check IGP metric stability, route-map MED policies, and 'bgp deterministic-med'. Implement BGP dampening. CPU impact from repeated best-path selection.
</answer>


[System] You are a network routing expert. Analyze the routing table, detect issues, and provide step-by-step reasoning. Use the format: <reasoning>...step-by-step analysis...</reasoning><answer>...concise answer...</answer>

[User]
Routing table:
B    10.150.53.0/28 [20/10] via 192.168.157.154
B    10.7.126.0/21 [20/5] via 192.168.90.33
C    192.168.1.0/24 is directly connected, GigabitEthernet0/0
B    10.177.213.0/16 [20/4] via 192.168.227.4
L    192.168.1.1/32 is directly connected, GigabitEthernet0/0
B    10.12.196.0/24 [20/2] via 192.168.217.160
B    10.138.101.0/19 [20/8] via 192.168.238.115
B    10.30.183.0/25 [20/1] via 192.168.232.151
B    10.180.86.0/25 [20/3] via 192.168.166.156
B    10.12.196.0/24 [20/210] via 192.168.179.178
B    10.25.62.0/29 [20/0] via 192.168.231.17
B    10.16.63.0/23 [20/6] via 192.168.92.151
B    10.46.254.0/24 [20/5] via 192.168.49.114
B    10.135.74.0/28 [20/2] via 192.168.169.199

Question: Identify all potential issues in this routing table and classify them by severity.

[Assistant]
<reasoning>
1. Observation: Two BGP routes to 10.12.196.0/24 exist with oscillating MED values: 2 via 192.168.217.160 and 210 via 192.168.179.178. The MED difference of 208 causes repeated best-path changes.
2. Analysis: MED flapping between BGP peers indicates inconsistent IGP metric redistribution. Possible causes: (a) IGP metric changes on the path to the next-hop, (b) route-map applying MED based on a dynamic metric (e.g., delay, load), (c) dual-homed peers with different IGP costs, or (d) BGP policy oscillation between two route-maps.
3. Context: BGP best-path selection runs for each prefix when MED changes. With many prefixes, this causes CPU spikes and route churn. The router may also send repeated updates to downstream peers, amplifying the instability. MED oscillation is a known cause of BGP route dampening activation.
4. Recommendation: Stabilize the IGP metric to the BGP next-hop addresses. Use 'set metric' with a fixed value in route-maps instead of dynamic IGP-derived MED. Consider using 'bgp deterministic-med' to ensure consistent comparison. Implement BGP route dampening to suppress flapping prefixes. If using IGP-derived MED, ensure IGP is stable (e.g., OSPF cost not flapping).
</reasoning>
<answer>
WARNING: BGP MED flapping for 10.12.196.0/24. MED oscillates between 2 and 210. Check IGP metric stability, route-map MED policies, and 'bgp deterministic-med'. Implement BGP dampening. CPU impact from repeated best-path selection.
</answer>


[System] You are a network routing expert. Analyze the routing table, detect issues, and provide step-by-step reasoning. Use the format: <reasoning>...step-by-step analysis...</reasoning><answer>...concise answer...</answer>

[User]
Routing table:
D    10.176.115.0/27 [90/750] via 192.168.141.122
C    192.168.1.0/24 is directly connected, GigabitEthernet0/0
D    10.61.199.0/20 [90/295] via 192.168.241.93
D    10.112.99.0/21 [90/255] via 192.168.131.24
D    10.151.15.0/30 [90/338] via 192.168.52.50
D    10.56.37.0/27 [90/385] via 192.168.115.119
D    10.225.75.0/28 [90/498] via 192.168.0.74
D    10.5.187.0/25 [90/382] via 192.168.47.71
D    10.96.91.0/21 [90/755] via 192.168.242.17
D    10.197.39.0/21 [90/138] via 192.168.200.248
D    10.23.70.0/24 [90/3432813] via 192.168.76.50
D    10.69.146.0/28 [90/668] via 192.168.25.254
L    192.168.1.1/32 is directly connected, GigabitEthernet0/0
D    10.236.77.0/19 [90/490] via 192.168.164.41
D    10.17.156.0/18 [90/502] via 192.168.137.117
D    10.48.65.0/22 [90/479] via 192.168.98.70

Question: Does this routing table have any routing inconsistencies?

[Assistant]
<reasoning>
1. Observation: EIGRP route to 10.23.70.0/24 has composite metric 3432813, while other EIGRP routes have metrics between 100 and 1000. The deviation is 3432x to 34328x from normal.
2. Analysis: EIGRP composite metric = (K1 * bandwidth + K2 * bandwidth/(256-load) + K3 * delay) * K5/(reliability + K4). A metric of 3432813 indicates either: (a) a very low-bandwidth link (e.g., T1 at 1544 kbps with high delay), (b) a satellite or MPLS link with high delay, (c) interface bandwidth misconfigured to 1 kbps, or (d) K-values mismatch between neighbors causing metric calculation divergence.
3. Context: EIGRP uses the composite metric for best-path and feasible successor selection. An abnormally high metric may prevent the route from being used even when it's the only path, or cause feasible successor rejection. The route may also indicate a SIA condition if the metric keeps increasing.
4. Recommendation: Verify 'bandwidth' and 'delay' interface parameters on all links toward 10.23.70.0/24. Check K-value consistency with 'show ip eigrp neighbors' and 'show ip protocols'. If the path includes a satellite/WAN link, consider adjusting delay to reflect actual latency. Verify no interface bandwidth is set to 1 kbps accidentally.
</reasoning>
<answer>
WARNING: Severe EIGRP metric skew for 10.23.70.0/24. Composite metric 3432813 is 3432x–34328x higher than normal (100–1000). Check interface bandwidth/delay, K-values consistency, and SIA conditions.
</answer>


[System] You are a network routing expert. Analyze the routing table, detect issues, and provide step-by-step reasoning. Use the format: <reasoning>...step-by-step analysis...</reasoning><answer>...concise answer...</answer>

[User]
Routing table:
O    10.226.91.0/27 [110/6] via 192.168.6.38, 10:29:31, Loopback21
O    10.159.46.0/19 [110/20] via 192.168.150.183, 07:27:31, Loopback84
O    10.69.178.0/23 [110/2] via 192.168.221.53, 03:33:29, Serial3/1:0
O    10.217.167.0/18 [110/20] via 192.168.134.170, 15:26:48, Port-channel7
O    10.8.1.0/24 [110/2] via 192.168.229.47, 02:21:22, GigabitEthernet2/2
O    10.3.134.0/26 [110/9] via 192.168.220.231, 20:19:21, GigabitEthernet3/2
C    192.168.1.0/24 is directly connected, GigabitEthernet0/0
O    10.130.136.0/24 [110/4] via 192.168.225.91, 04:41:47, Loopback8
O    10.48.2.0/24 [110/981] via 192.168.75.164, 09:35:34, Loopback8
O    10.148.27.0/21 [110/10] via 192.168.178.233, 20:36:21, Port-channel2
O    10.17.120.0/24 [110/19] via 192.168.92.80, 20:44:29, Serial2/1:1
L    192.168.1.1/32 is directly connected, GigabitEthernet0/0
O    10.7.83.0/29 [110/7] via 192.168.139.124, 04:30:52, FastEthernet1/3
O    10.96.205.0/21 [110/7] via 192.168.244.113, 08:49:04, Port-channel3

Question: Does this routing table have any routing inconsistencies?

[Assistant]
<reasoning>
1. Observation: Intra-area route 10.8.1.0/24 has metric 2, while inter-area route 10.48.2.0/24 has metric 981. The inter-area metric is 979 higher despite both destinations being roughly equidistant.
2. Analysis: OSPF inter-area routes are calculated as the sum of intra-area cost to the ABR plus the cost from ABR to destination. An abnormally high inter-area metric suggests: (a) suboptimal ABR placement, (b) a high-cost link in the backbone (Area 0), (c) virtual link with accumulated cost, or (d) summary LSA (Type 3) advertising a high metric from the ABR.
3. Context: Inter-area metric inconsistency causes suboptimal routing—traffic to 10.48.2.0/24 takes a much longer path than necessary. This can create asymmetric routing if return traffic takes a shorter intra-area path. It also complicates traffic engineering and SLA compliance.
4. Recommendation: Verify ABR placement and backbone topology. Check 'show ip ospf database summary' for the advertised metric of 10.48.2.0/24. Ensure virtual links (if used) are not adding excessive cost. Consider using 'area range' with 'cost' override on ABRs to normalize inter-area metrics. Verify all backbone links have consistent bandwidth settings.
</reasoning>
<answer>
WARNING: OSPF inter-area metric inconsistency. 10.48.2.0/24 metric 981 is 979 higher than intra-area 10.8.1.0/24 (2). Check ABR placement, backbone link costs, virtual links, and summary LSA metrics. Suboptimal routing likely.
</answer>


[System] You are a network routing expert. Analyze the routing table, detect issues, and provide step-by-step reasoning. Use the format: <reasoning>...step-by-step analysis...</reasoning><answer>...concise answer...</answer>

[User]
Routing table:
D    10.233.157.0/28 [90/183] via 192.168.18.115
O    10.36.54.0/19 [110/6] via 192.168.177.204, 12:50:06, Port-channel3
D    10.2.251.0/24 [90/165332] via 192.168.163.107
L    192.168.1.1/32 is directly connected, GigabitEthernet0/0
O    10.6.213.0/20 [110/17] via 192.168.100.183, 20:08:34, FastEthernet2/3
O    10.245.74.0/29 [110/13] via 192.168.113.29, 11:22:08, Loopback19
D    10.37.225.0/29 [90/372] via 192.168.136.43
O    10.2.251.0/24 [110/10] via 192.168.228.193, 12:52:58, FastEthernet2/0
O    10.117.161.0/28 [110/6] via 192.168.107.190, 13:45:23, Serial0/0:1
D    10.79.167.0/21 [90/762] via 192.168.183.58
C    192.168.1.0/24 is directly connected, GigabitEthernet0/0
O    10.134.49.0/26 [110/20] via 192.168.180.154, 19:11:14, Serial2/1:1

Question: Analyze this routing table for Administrative Distance conflicts.

[Assistant]
<reasoning>
1. Observation: Network 10.2.251.0/24 appears in both OSPF (metric 10, AD 110) and EIGRP (metric 165332, AD 90). The metrics differ by 16533x, but EIGRP's lower AD (90 < 110) makes it the active route.
2. Analysis: OSPF and EIGRP use completely different metric scales. OSPF cost is based on cumulative link bandwidth (typically 1–65535), while EIGRP composite metric combines bandwidth, delay, load, and reliability (typically 100–10,000,000). Direct comparison is meaningless. However, the coexistence of both protocols for the same prefix indicates route redistribution or accidental dual-protocol deployment.
3. Context: If redistribution is intentional, metrics must be scaled appropriately (e.g., OSPF→EIGRP metric translation). If accidental, the protocols compete for RIB installation, causing route flapping if AD values are manipulated. The EIGRP path may be suboptimal despite lower AD if the OSPF path is actually better in terms of latency/hops.
4. Recommendation: Verify if dual-protocol learning is intentional. If redistributing, use route-maps with metric scaling (e.g., 'set metric 10000 100 255 1 1500' for EIGRP). If accidental, remove one protocol from the interface or use distribute-lists. Ensure AD values reflect true path preference—consider 'distance eigrp' or 'distance ospf' adjustments.
</reasoning>
<answer>
WARNING: Inconsistent metrics between protocols for 10.2.251.0/24. OSPF metric 10 vs EIGRP metric 165332 (different scales). EIGRP wins due to lower AD (90). Verify redistribution scaling or remove accidental dual-protocol deployment.
</answer>


[System] You are a network routing expert. Analyze the routing table, detect issues, and provide step-by-step reasoning. Use the format: <reasoning>...step-by-step analysis...</reasoning><answer>...concise answer...</answer>

[User]
Routing table:
D    10.20.241.0/18 [90/223] via 192.168.242.104
D    10.10.221.0/23 [90/712] via 192.168.26.165
D    10.149.222.0/17 [90/203] via 192.168.103.168
D    10.163.48.0/20 [90/366] via 192.168.255.251
D    10.252.250.0/27 [90/420] via 192.168.219.16
D    10.5.15.0/21 [90/420] via 192.168.103.8
D    10.182.62.0/20 [90/532] via 192.168.60.63
D    10.210.171.0/24 [90/283] via 192.168.112.11
D    10.42.175.0/24 [90/9330076] via 192.168.185.52
D    10.176.206.0/24 [90/763] via 192.168.41.163
D    10.115.106.0/20 [90/801] via 192.168.109.118
L    192.168.1.1/32 is directly connected, GigabitEthernet0/0
C    192.168.1.0/24 is directly connected, GigabitEthernet0/0

Question: Does this routing table have any routing inconsistencies?

[Assistant]
<reasoning>
1. Observation: EIGRP route to 10.42.175.0/24 has composite metric 9330076, while other EIGRP routes have metrics between 100 and 1000. The deviation is 9330x to 93300x from normal.
2. Analysis: EIGRP composite metric = (K1 * bandwidth + K2 * bandwidth/(256-load) + K3 * delay) * K5/(reliability + K4). A metric of 9330076 indicates either: (a) a very low-bandwidth link (e.g., T1 at 1544 kbps with high delay), (b) a satellite or MPLS link with high delay, (c) interface bandwidth misconfigured to 1 kbps, or (d) K-values mismatch between neighbors causing metric calculation divergence.
3. Context: EIGRP uses the composite metric for best-path and feasible successor selection. An abnormally high metric may prevent the route from being used even when it's the only path, or cause feasible successor rejection. The route may also indicate a SIA condition if the metric keeps increasing.
4. Recommendation: Verify 'bandwidth' and 'delay' interface parameters on all links toward 10.42.175.0/24. Check K-value consistency with 'show ip eigrp neighbors' and 'show ip protocols'. If the path includes a satellite/WAN link, consider adjusting delay to reflect actual latency. Verify no interface bandwidth is set to 1 kbps accidentally.
</reasoning>
<answer>
WARNING: Severe EIGRP metric skew for 10.42.175.0/24. Composite metric 9330076 is 9330x–93300x higher than normal (100–1000). Check interface bandwidth/delay, K-values consistency, and SIA conditions.
</answer>


[System] You are a network routing expert. Analyze the routing table, detect issues, and provide step-by-step reasoning. Use the format: <reasoning>...step-by-step analysis...</reasoning><answer>...concise answer...</answer>

[User]
Routing table:
D    10.33.47.0/24 [90/438989] via 192.168.55.175
O    10.85.40.0/27 [110/20] via 192.168.115.178, 05:42:10, FastEthernet1/1
D    10.109.114.0/18 [90/379] via 192.168.65.223
D    10.98.95.0/19 [90/694] via 192.168.56.92
D    10.88.218.0/19 [90/550] via 192.168.239.157
D    10.72.77.0/30 [90/191] via 192.168.173.217
O    10.185.115.0/23 [110/11] via 192.168.205.116, 05:57:53, GigabitEthernet3/1
C    192.168.1.0/24 is directly connected, GigabitEthernet0/0
O    10.232.214.0/22 [110/12] via 192.168.120.131, 11:59:58, GigabitEthernet1/1
O    10.33.47.0/24 [110/17] via 192.168.56.239, 03:40:17, Port-channel8
O    10.31.67.0/24 [110/15] via 192.168.15.201, 23:41:36, GigabitEthernet3/1
L    192.168.1.1/32 is directly connected, GigabitEthernet0/0

Question: Analyze this routing table for Administrative Distance conflicts.

[Assistant]
<reasoning>
1. Observation: Network 10.33.47.0/24 appears in both OSPF (metric 17, AD 110) and EIGRP (metric 438989, AD 90). The metrics differ by 25822x, but EIGRP's lower AD (90 < 110) makes it the active route.
2. Analysis: OSPF and EIGRP use completely different metric scales. OSPF cost is based on cumulative link bandwidth (typically 1–65535), while EIGRP composite metric combines bandwidth, delay, load, and reliability (typically 100–10,000,000). Direct comparison is meaningless. However, the coexistence of both protocols for the same prefix indicates route redistribution or accidental dual-protocol deployment.
3. Context: If redistribution is intentional, metrics must be scaled appropriately (e.g., OSPF→EIGRP metric translation). If accidental, the protocols compete for RIB installation, causing route flapping if AD values are manipulated. The EIGRP path may be suboptimal despite lower AD if the OSPF path is actually better in terms of latency/hops.
4. Recommendation: Verify if dual-protocol learning is intentional. If redistributing, use route-maps with metric scaling (e.g., 'set metric 10000 100 255 1 1500' for EIGRP). If accidental, remove one protocol from the interface or use distribute-lists. Ensure AD values reflect true path preference—consider 'distance eigrp' or 'distance ospf' adjustments.
</reasoning>
<answer>
WARNING: Inconsistent metrics between protocols for 10.33.47.0/24. OSPF metric 17 vs EIGRP metric 438989 (different scales). EIGRP wins due to lower AD (90). Verify redistribution scaling or remove accidental dual-protocol deployment.
</answer>


[System] You are a network routing expert. Analyze the routing table, detect issues, and provide step-by-step reasoning. Use the format: <reasoning>...step-by-step analysis...</reasoning><answer>...concise answer...</answer>

[User]
Routing table:
L    192.168.1.1/32 is directly connected, GigabitEthernet0/0
O    10.78.5.0/24 [110/11] via 192.168.227.187, 09:55:20, Serial3/1:1
O    10.100.153.0/18 [110/20] via 192.168.220.172, 20:31:43, FastEthernet3/3
O    10.78.2.0/24 [110/4] via 192.168.244.29, 04:26:16, FastEthernet0/2
C    192.168.1.0/24 is directly connected, GigabitEthernet0/0
O    10.155.193.0/27 [110/16] via 192.168.134.89, 01:47:39, FastEthernet1/2
O    10.78.0.0/24 [110/19] via 192.168.157.192, 23:11:45, GigabitEthernet0/2
O    10.30.157.0/27 [110/18] via 192.168.18.205, 22:40:56, Serial2/1:0
O    10.78.60.0/24 [110/1416] via 192.168.15.53, 07:55:44, FastEthernet2/3
O    10.78.1.0/24 [110/5] via 192.168.234.152, 19:32:59, FastEthernet3/1
O    10.78.3.0/24 [110/11] via 192.168.10.114, 14:37:07, FastEthernet3/0
O    10.84.51.0/19 [110/12] via 192.168.197.33, 06:39:35, Port-channel7
O    10.146.179.0/29 [110/14] via 192.168.179.193, 00:26:33, Port-channel4
O    10.78.4.0/24 [110/12] via 192.168.49.59, 12:17:28, Loopback8

Question: Identify all potential issues in this routing table and classify them by severity.

[Assistant]
<reasoning>
1. Observation: OSPF route to 10.78.60.0/24 has metric 1416, while all other OSPF routes in the same area have metrics between 2 and 20. The deviation is 70x to 708x from the normal range.
2. Analysis: OSPF metric is calculated as the sum of interface costs (reference bandwidth / interface bandwidth). A metric of 1416 suggests either: (a) a very low-bandwidth path (e.g., serial link at 64 kbps), (b) manual cost misconfiguration, (c) reference bandwidth mismatch between routers, or (d) a routing loop causing accumulated cost.
3. Context: This skewed metric makes the path appear much longer than it is. Traffic to 10.78.60.0/24 will be routed suboptimally if an alternate path exists. In a hierarchical design, such metrics can break traffic engineering and cause hot-potato routing issues.
4. Recommendation: Verify interface bandwidth settings on all links toward 10.78.60.0/24. Check 'auto-cost reference-bandwidth' consistency across all OSPF routers. If the path includes a low-speed link, consider upgrading or using a tunnel. Verify no manual 'ip ospf cost' override is applied incorrectly.
</reasoning>
<answer>
WARNING: Severe OSPF metric skew for 10.78.60.0/24. Metric 1416 is 70x–708x higher than area average (2–20). Check interface bandwidth, reference-bandwidth consistency, and manual cost overrides. Suboptimal routing likely.
</answer>


[System] You are a network routing expert. Analyze the routing table, detect issues, and provide step-by-step reasoning. Use the format: <reasoning>...step-by-step analysis...</reasoning><answer>...concise answer...</answer>

[User]
Routing table:
O    10.137.2.0/24 [110/5] via 192.168.140.209, 02:56:29, FastEthernet1/0
O    10.137.0.0/24 [110/11] via 192.168.40.99, 08:29:31, FastEthernet2/1
O    10.137.99.0/24 [110/2052] via 192.168.212.248, 07:01:19, GigabitEthernet0/0
O    10.137.4.0/24 [110/10] via 192.168.110.29, 18:18:36, Port-channel4
L    192.168.1.1/32 is directly connected, GigabitEthernet0/0
O    10.137.5.0/24 [110/19] via 192.168.137.172, 03:27:10, FastEthernet0/2
O    10.236.218.0/26 [110/13] via 192.168.61.176, 12:18:52, Port-channel5
O    10.48.179.0/21 [110/3] via 192.168.233.156, 19:13:38, Loopback40
O    10.137.1.0/24 [110/16] via 192.168.212.74, 14:07:33, FastEthernet2/3
O    10.182.29.0/27 [110/2] via 192.168.223.225, 09:49:26, Serial2/1:0
O    10.137.6.0/24 [110/3] via 192.168.54.176, 08:37:53, Serial1/0:1
C    192.168.1.0/24 is directly connected, GigabitEthernet0/0
O    10.137.7.0/24 [110/12] via 192.168.32.75, 02:00:26, FastEthernet2/2
O    10.137.3.0/24 [110/19] via 192.168.169.105, 05:22:35, FastEthernet0/2

Question: Identify all potential issues in this routing table and classify them by severity.

[Assistant]
<reasoning>
1. Observation: OSPF route to 10.137.99.0/24 has metric 2052, while all other OSPF routes in the same area have metrics between 2 and 20. The deviation is 102x to 1026x from the normal range.
2. Analysis: OSPF metric is calculated as the sum of interface costs (reference bandwidth / interface bandwidth). A metric of 2052 suggests either: (a) a very low-bandwidth path (e.g., serial link at 64 kbps), (b) manual cost misconfiguration, (c) reference bandwidth mismatch between routers, or (d) a routing loop causing accumulated cost.
3. Context: This skewed metric makes the path appear much longer than it is. Traffic to 10.137.99.0/24 will be routed suboptimally if an alternate path exists. In a hierarchical design, such metrics can break traffic engineering and cause hot-potato routing issues.
4. Recommendation: Verify interface bandwidth settings on all links toward 10.137.99.0/24. Check 'auto-cost reference-bandwidth' consistency across all OSPF routers. If the path includes a low-speed link, consider upgrading or using a tunnel. Verify no manual 'ip ospf cost' override is applied incorrectly.
</reasoning>
<answer>
WARNING: Severe OSPF metric skew for 10.137.99.0/24. Metric 2052 is 102x–1026x higher than area average (2–20). Check interface bandwidth, reference-bandwidth consistency, and manual cost overrides. Suboptimal routing likely.
</answer>


[System] You are a network routing expert. Analyze the routing table, detect issues, and provide step-by-step reasoning. Use the format: <reasoning>...step-by-step analysis...</reasoning><answer>...concise answer...</answer>

[User]
Routing table:
D    10.225.12.0/28 [90/479] via 192.168.146.105
L    192.168.1.1/32 is directly connected, GigabitEthernet0/0
D    10.7.214.0/24 [90/3924194] via 192.168.59.178
D    10.179.128.0/28 [90/284] via 192.168.245.3
D    10.111.29.0/17 [90/125] via 192.168.117.46
C    192.168.1.0/24 is directly connected, GigabitEthernet0/0
D    10.150.27.0/17 [90/233] via 192.168.169.111
D    10.196.153.0/30 [90/205] via 192.168.131.1
D    10.225.97.0/30 [90/419] via 192.168.26.107
D    10.187.233.0/17 [90/164] via 192.168.27.75
D    10.53.36.0/25 [90/240] via 192.168.198.10
D    10.211.238.0/16 [90/463] via 192.168.11.222
D    10.193.183.0/16 [90/476] via 192.168.182.99

Question: Does this routing table have any routing inconsistencies?

[Assistant]
<reasoning>
1. Observation: EIGRP route to 10.7.214.0/24 has composite metric 3924194, while other EIGRP routes have metrics between 100 and 1000. The deviation is 3924x to 39241x from normal.
2. Analysis: EIGRP composite metric = (K1 * bandwidth + K2 * bandwidth/(256-load) + K3 * delay) * K5/(reliability + K4). A metric of 3924194 indicates either: (a) a very low-bandwidth link (e.g., T1 at 1544 kbps with high delay), (b) a satellite or MPLS link with high delay, (c) interface bandwidth misconfigured to 1 kbps, or (d) K-values mismatch between neighbors causing metric calculation divergence.
3. Context: EIGRP uses the composite metric for best-path and feasible successor selection. An abnormally high metric may prevent the route from being used even when it's the only path, or cause feasible successor rejection. The route may also indicate a SIA condition if the metric keeps increasing.
4. Recommendation: Verify 'bandwidth' and 'delay' interface parameters on all links toward 10.7.214.0/24. Check K-value consistency with 'show ip eigrp neighbors' and 'show ip protocols'. If the path includes a satellite/WAN link, consider adjusting delay to reflect actual latency. Verify no interface bandwidth is set to 1 kbps accidentally.
</reasoning>
<answer>
WARNING: Severe EIGRP metric skew for 10.7.214.0/24. Composite metric 3924194 is 3924x–39241x higher than normal (100–1000). Check interface bandwidth/delay, K-values consistency, and SIA conditions.
</answer>


[System] You are a network routing expert. Analyze the routing table, detect issues, and provide step-by-step reasoning. Use the format: <reasoning>...step-by-step analysis...</reasoning><answer>...concise answer...</answer>

[User]
Routing table:
O    10.133.180.0/20 [110/12] via 192.168.155.193, 03:34:04, Port-channel8
O    10.244.201.0/30 [110/17] via 192.168.223.166, 07:17:58, Loopback48
O    10.2.169.0/16 [110/14] via 192.168.4.211, 06:36:47, FastEthernet0/0
O    10.189.142.0/18 [110/4] via 192.168.213.129, 11:15:06, Loopback24
O    10.134.62.0/16 [110/8] via 192.168.86.192, 11:49:42, Port-channel4
O    10.29.241.0/28 [110/4] via 192.168.204.187, 00:31:54, FastEthernet2/1
O    10.222.149.0/23 [110/2] via 192.168.105.57, 19:56:16, Port-channel7
L    192.168.1.1/32 is directly connected, GigabitEthernet0/0
O    10.31.121.0/24 [110/4] via 192.168.127.246, 00:00:07, Loopback71
O    10.38.215.0/19 [110/11] via 192.168.191.227, 06:12:11, Serial3/1:1
O    10.172.26.0/26 [110/7] via 192.168.220.8, 03:04:06, GigabitEthernet1/1
O    10.224.134.0/17 [110/12] via 192.168.192.90, 16:22:17, Loopback16
O    10.196.48.0/28 [110/12] via 192.168.225.229, 03:59:48, Port-channel2
C    192.168.1.0/24 is directly connected, GigabitEthernet0/0
O    10.31.121.0/24 [110/152] via 192.168.99.182, 00:00:27, Loopback81
O    10.104.84.0/25 [110/10] via 192.168.150.67, 20:15:31, Loopback42
O    10.55.158.0/17 [110/9] via 192.168.67.213, 02:47:59, FastEthernet2/0

Question: Does this routing table have any routing inconsistencies?

[Assistant]
<reasoning>
1. Observation: Two OSPF routes to 10.31.121.0/24 exist with different metrics: 4 via 192.168.127.246 (recent) and 152 via 192.168.99.182 (more recent). The metric oscillated by 148 within 30 seconds.
2. Analysis: Metric flapping in OSPF indicates interface cost instability. Possible causes: (a) interface bandwidth auto-negotiation flapping between speeds (e.g., 1Gbps ↔ 100Mbps), (b) reference bandwidth change on an upstream router, (c) LSA refresh from a router with inconsistent cost, or (d) a link with intermittent congestion causing OSPF to recalculate.
3. Context: Metric flapping triggers repeated SPF calculations, consuming CPU. It also causes route churn in the RIB and FIB, leading to packet loss and out-of-order delivery. CEF may alternate between next-hops, causing micro-looping.
4. Recommendation: Check interface speed/duplex on all links toward 10.31.121.0/24 with 'show interface'. Verify 'auto-cost reference-bandwidth' is identical on all routers in the area. Check for LSA Type 1/2 flooding storms. Consider enabling OSPF SPF throttling ('timers throttle spf') to dampen recalculation frequency.
</reasoning>
<answer>
WARNING: OSPF metric flapping for 10.31.121.0/24. Metric oscillated between 4 and 152 within 30 seconds. Check interface speed/duplex negotiation, reference-bandwidth consistency, and LSA flooding. Enable SPF throttling to reduce CPU impact.
</answer>


[System] You are a network routing expert. Analyze the routing table, detect issues, and provide step-by-step reasoning. Use the format: <reasoning>...step-by-step analysis...</reasoning><answer>...concise answer...</answer>

[User]
Routing table:
B    10.3.170.0/24 [20/103] via 192.168.187.5
B    10.82.8.0/27 [20/13] via 192.168.11.203
B    10.207.252.0/28 [20/0] via 192.168.45.146
B    10.3.170.0/24 [20/2] via 192.168.131.140
B    10.76.24.0/18 [20/4] via 192.168.123.73
B    10.72.44.0/24 [20/2] via 192.168.191.214
B    10.94.60.0/19 [20/6] via 192.168.197.128
L    192.168.1.1/32 is directly connected, GigabitEthernet0/0
C    192.168.1.0/24 is directly connected, GigabitEthernet0/0
B    10.112.219.0/30 [20/3] via 192.168.203.230
B    10.185.59.0/17 [20/8] via 192.168.160.252
B    10.8.55.0/22 [20/10] via 192.168.233.202
B    10.75.255.0/20 [20/7] via 192.168.25.201
B    10.139.217.0/18 [20/1] via 192.168.149.8
B    10.145.139.0/20 [20/0] via 192.168.148.144

Question: Identify all potential issues in this routing table and classify them by severity.

[Assistant]
<reasoning>
1. Observation: Two BGP routes to 10.3.170.0/24 exist with oscillating MED values: 2 via 192.168.131.140 and 103 via 192.168.187.5. The MED difference of 101 causes repeated best-path changes.
2. Analysis: MED flapping between BGP peers indicates inconsistent IGP metric redistribution. Possible causes: (a) IGP metric changes on the path to the next-hop, (b) route-map applying MED based on a dynamic metric (e.g., delay, load), (c) dual-homed peers with different IGP costs, or (d) BGP policy oscillation between two route-maps.
3. Context: BGP best-path selection runs for each prefix when MED changes. With many prefixes, this causes CPU spikes and route churn. The router may also send repeated updates to downstream peers, amplifying the instability. MED oscillation is a known cause of BGP route dampening activation.
4. Recommendation: Stabilize the IGP metric to the BGP next-hop addresses. Use 'set metric' with a fixed value in route-maps instead of dynamic IGP-derived MED. Consider using 'bgp deterministic-med' to ensure consistent comparison. Implement BGP route dampening to suppress flapping prefixes. If using IGP-derived MED, ensure IGP is stable (e.g., OSPF cost not flapping).
</reasoning>
<answer>
WARNING: BGP MED flapping for 10.3.170.0/24. MED oscillates between 2 and 103. Check IGP metric stability, route-map MED policies, and 'bgp deterministic-med'. Implement BGP dampening. CPU impact from repeated best-path selection.
</answer>


[System] You are a network routing expert. Analyze the routing table, detect issues, and provide step-by-step reasoning. Use the format: <reasoning>...step-by-step analysis...</reasoning><answer>...concise answer...</answer>

[User]
Routing table:
O    10.236.245.0/25 [110/19] via 192.168.204.144, 20:26:24, GigabitEthernet0/0
D    10.42.164.0/23 [90/263] via 192.168.204.243
O    10.0.61.0/26 [110/14] via 192.168.16.211, 12:56:22, GigabitEthernet1/1
D    10.28.51.0/24 [90/328149] via 192.168.30.216
D    10.168.253.0/27 [90/762] via 192.168.34.32
L    192.168.1.1/32 is directly connected, GigabitEthernet0/0
D    10.216.3.0/22 [90/459] via 192.168.22.226
O    10.136.193.0/20 [110/2] via 192.168.58.23, 04:23:39, Serial2/0:0
C    192.168.1.0/24 is directly connected, GigabitEthernet0/0
O    10.194.197.0/24 [110/7] via 192.168.125.23, 19:16:40, GigabitEthernet1/0
D    10.150.103.0/16 [90/400] via 192.168.216.197
O    10.28.51.0/24 [110/17] via 192.168.42.181, 22:32:56, GigabitEthernet1/2
O    10.15.114.0/28 [110/5] via 192.168.136.90, 13:15:43, FastEthernet2/3
D    10.231.114.0/18 [90/919] via 192.168.58.175
D    10.62.50.0/19 [90/751] via 192.168.95.207

Question: Analyze this routing table for Administrative Distance conflicts.

[Assistant]
<reasoning>
1. Observation: Network 10.28.51.0/24 appears in both OSPF (metric 17, AD 110) and EIGRP (metric 328149, AD 90). The metrics differ by 19302x, but EIGRP's lower AD (90 < 110) makes it the active route.
2. Analysis: OSPF and EIGRP use completely different metric scales. OSPF cost is based on cumulative link bandwidth (typically 1–65535), while EIGRP composite metric combines bandwidth, delay, load, and reliability (typically 100–10,000,000). Direct comparison is meaningless. However, the coexistence of both protocols for the same prefix indicates route redistribution or accidental dual-protocol deployment.
3. Context: If redistribution is intentional, metrics must be scaled appropriately (e.g., OSPF→EIGRP metric translation). If accidental, the protocols compete for RIB installation, causing route flapping if AD values are manipulated. The EIGRP path may be suboptimal despite lower AD if the OSPF path is actually better in terms of latency/hops.
4. Recommendation: Verify if dual-protocol learning is intentional. If redistributing, use route-maps with metric scaling (e.g., 'set metric 10000 100 255 1 1500' for EIGRP). If accidental, remove one protocol from the interface or use distribute-lists. Ensure AD values reflect true path preference—consider 'distance eigrp' or 'distance ospf' adjustments.
</reasoning>
<answer>
WARNING: Inconsistent metrics between protocols for 10.28.51.0/24. OSPF metric 17 vs EIGRP metric 328149 (different scales). EIGRP wins due to lower AD (90). Verify redistribution scaling or remove accidental dual-protocol deployment.
</answer>


[System] You are a network routing expert. Analyze the routing table, detect issues, and provide step-by-step reasoning. Use the format: <reasoning>...step-by-step analysis...</reasoning><answer>...concise answer...</answer>

[User]
Routing table:
O    10.175.21.0/23 [110/8] via 192.168.239.114, 08:51:01, Port-channel5
O    10.14.201.0/24 [110/149] via 192.168.60.55, 00:00:17, Serial3/1:1
O    10.163.248.0/21 [110/3] via 192.168.187.253, 01:52:48, Port-channel1
O    10.14.201.0/24 [110/2] via 192.168.201.197, 00:00:11, FastEthernet2/3
L    192.168.1.1/32 is directly connected, GigabitEthernet0/0
O    10.139.18.0/23 [110/7] via 192.168.171.26, 13:40:47, FastEthernet0/2
O    10.57.49.0/16 [110/9] via 192.168.226.83, 22:50:00, GigabitEthernet3/0
O    10.28.142.0/21 [110/9] via 192.168.72.146, 06:36:01, GigabitEthernet1/0
O    10.63.239.0/18 [110/12] via 192.168.67.78, 18:55:48, Port-channel5
O    10.126.19.0/30 [110/13] via 192.168.109.75, 19:57:28, Serial1/1:0
O    10.2.79.0/22 [110/10] via 192.168.137.188, 19:21:40, GigabitEthernet0/3
O    10.58.176.0/27 [110/5] via 192.168.110.128, 04:57:30, GigabitEthernet0/3
C    192.168.1.0/24 is directly connected, GigabitEthernet0/0
O    10.184.62.0/20 [110/5] via 192.168.110.132, 01:12:46, Serial3/1:0
O    10.140.216.0/20 [110/6] via 192.168.124.237, 14:08:44, GigabitEthernet0/3

Question: Does this routing table have any routing inconsistencies?

[Assistant]
<reasoning>
1. Observation: Two OSPF routes to 10.14.201.0/24 exist with different metrics: 2 via 192.168.201.197 (recent) and 149 via 192.168.60.55 (more recent). The metric oscillated by 147 within 30 seconds.
2. Analysis: Metric flapping in OSPF indicates interface cost instability. Possible causes: (a) interface bandwidth auto-negotiation flapping between speeds (e.g., 1Gbps ↔ 100Mbps), (b) reference bandwidth change on an upstream router, (c) LSA refresh from a router with inconsistent cost, or (d) a link with intermittent congestion causing OSPF to recalculate.
3. Context: Metric flapping triggers repeated SPF calculations, consuming CPU. It also causes route churn in the RIB and FIB, leading to packet loss and out-of-order delivery. CEF may alternate between next-hops, causing micro-looping.
4. Recommendation: Check interface speed/duplex on all links toward 10.14.201.0/24 with 'show interface'. Verify 'auto-cost reference-bandwidth' is identical on all routers in the area. Check for LSA Type 1/2 flooding storms. Consider enabling OSPF SPF throttling ('timers throttle spf') to dampen recalculation frequency.
</reasoning>
<answer>
WARNING: OSPF metric flapping for 10.14.201.0/24. Metric oscillated between 2 and 149 within 30 seconds. Check interface speed/duplex negotiation, reference-bandwidth consistency, and LSA flooding. Enable SPF throttling to reduce CPU impact.
</answer>


[System] You are a network routing expert. Analyze the routing table, detect issues, and provide step-by-step reasoning. Use the format: <reasoning>...step-by-step analysis...</reasoning><answer>...concise answer...</answer>

[User]
Routing table:
D    10.145.87.0/25 [90/346] via 192.168.140.199
D    10.55.227.0/28 [90/870] via 192.168.26.51
D    10.65.136.0/28 [90/104] via 192.168.136.102
C    192.168.1.0/24 is directly connected, GigabitEthernet0/0
D    10.3.0.0/17 [90/108] via 192.168.28.227
D    10.91.200.0/17 [90/486] via 192.168.189.104
D    10.142.235.0/24 [90/381] via 192.168.38.197
L    192.168.1.1/32 is directly connected, GigabitEthernet0/0
D    10.231.16.0/19 [90/637] via 192.168.18.80
D    10.79.252.0/19 [90/482] via 192.168.112.10
D    10.46.21.0/24 [90/7253742] via 192.168.160.163
D    10.9.10.0/23 [90/118] via 192.168.26.197

Question: Does this routing table have any routing inconsistencies?

[Assistant]
<reasoning>
1. Observation: EIGRP route to 10.46.21.0/24 has composite metric 7253742, while other EIGRP routes have metrics between 100 and 1000. The deviation is 7253x to 72537x from normal.
2. Analysis: EIGRP composite metric = (K1 * bandwidth + K2 * bandwidth/(256-load) + K3 * delay) * K5/(reliability + K4). A metric of 7253742 indicates either: (a) a very low-bandwidth link (e.g., T1 at 1544 kbps with high delay), (b) a satellite or MPLS link with high delay, (c) interface bandwidth misconfigured to 1 kbps, or (d) K-values mismatch between neighbors causing metric calculation divergence.
3. Context: EIGRP uses the composite metric for best-path and feasible successor selection. An abnormally high metric may prevent the route from being used even when it's the only path, or cause feasible successor rejection. The route may also indicate a SIA condition if the metric keeps increasing.
4. Recommendation: Verify 'bandwidth' and 'delay' interface parameters on all links toward 10.46.21.0/24. Check K-value consistency with 'show ip eigrp neighbors' and 'show ip protocols'. If the path includes a satellite/WAN link, consider adjusting delay to reflect actual latency. Verify no interface bandwidth is set to 1 kbps accidentally.
</reasoning>
<answer>
WARNING: Severe EIGRP metric skew for 10.46.21.0/24. Composite metric 7253742 is 7253x–72537x higher than normal (100–1000). Check interface bandwidth/delay, K-values consistency, and SIA conditions.
</answer>


[System] You are a network routing expert. Analyze the routing table, detect issues, and provide step-by-step reasoning. Use the format: <reasoning>...step-by-step analysis...</reasoning><answer>...concise answer...</answer>

[User]
Routing table:
O    10.143.2.0/24 [110/17] via 192.168.169.83, 05:12:51, Loopback40
O    10.143.4.0/24 [110/10] via 192.168.65.111, 14:16:09, Serial0/1:1
O    10.253.107.0/22 [110/12] via 192.168.180.166, 00:17:35, GigabitEthernet3/1
O    10.143.3.0/24 [110/13] via 192.168.237.57, 04:28:47, Serial3/1:0
O    10.143.0.0/24 [110/16] via 192.168.183.175, 02:04:49, Port-channel6
O    10.112.61.0/26 [110/2] via 192.168.137.84, 19:40:23, FastEthernet3/2
O    10.143.5.0/24 [110/12] via 192.168.137.60, 09:36:29, FastEthernet0/2
C    192.168.1.0/24 is directly connected, GigabitEthernet0/0
O    10.129.66.0/21 [110/17] via 192.168.212.214, 00:02:48, Loopback43
O    10.143.1.0/24 [110/17] via 192.168.44.207, 10:27:32, Serial2/0:0
O    10.143.90.0/24 [110/2643] via 192.168.204.6, 21:26:21, Port-channel6
L    192.168.1.1/32 is directly connected, GigabitEthernet0/0

Question: Identify all potential issues in this routing table and classify them by severity.

[Assistant]
<reasoning>
1. Observation: OSPF route to 10.143.90.0/24 has metric 2643, while all other OSPF routes in the same area have metrics between 2 and 20. The deviation is 132x to 1321x from the normal range.
2. Analysis: OSPF metric is calculated as the sum of interface costs (reference bandwidth / interface bandwidth). A metric of 2643 suggests either: (a) a very low-bandwidth path (e.g., serial link at 64 kbps), (b) manual cost misconfiguration, (c) reference bandwidth mismatch between routers, or (d) a routing loop causing accumulated cost.
3. Context: This skewed metric makes the path appear much longer than it is. Traffic to 10.143.90.0/24 will be routed suboptimally if an alternate path exists. In a hierarchical design, such metrics can break traffic engineering and cause hot-potato routing issues.
4. Recommendation: Verify interface bandwidth settings on all links toward 10.143.90.0/24. Check 'auto-cost reference-bandwidth' consistency across all OSPF routers. If the path includes a low-speed link, consider upgrading or using a tunnel. Verify no manual 'ip ospf cost' override is applied incorrectly.
</reasoning>
<answer>
WARNING: Severe OSPF metric skew for 10.143.90.0/24. Metric 2643 is 132x–1321x higher than area average (2–20). Check interface bandwidth, reference-bandwidth consistency, and manual cost overrides. Suboptimal routing likely.
</answer>


[System] You are a network routing expert. Analyze the routing table, detect issues, and provide step-by-step reasoning. Use the format: <reasoning>...step-by-step analysis...</reasoning><answer>...concise answer...</answer>

[User]
Routing table:
O    10.179.113.0/22 [110/16] via 192.168.106.67, 21:45:11, Loopback78
D    10.84.231.0/30 [90/449] via 192.168.187.164
C    192.168.1.0/24 is directly connected, GigabitEthernet0/0
D    10.70.138.0/16 [90/681] via 192.168.32.213
O    10.4.207.0/30 [110/19] via 192.168.132.38, 20:45:40, GigabitEthernet1/0
O    10.251.144.0/21 [110/20] via 192.168.120.88, 05:26:20, Port-channel7
D    10.73.158.0/28 [90/920] via 192.168.163.94
D    10.202.75.0/22 [90/183] via 192.168.73.177
O    10.148.9.0/16 [110/4] via 192.168.248.27, 09:27:32, Serial1/1:0
L    192.168.1.1/32 is directly connected, GigabitEthernet0/0
O    10.4.253.0/24 [110/15] via 192.168.245.163, 10:18:45, GigabitEthernet2/2
D    10.4.253.0/24 [90/300850] via 192.168.253.139
D    10.40.110.0/16 [90/223] via 192.168.199.216
O    10.14.157.0/18 [110/5] via 192.168.188.39, 23:57:44, Serial3/0:0

Question: Analyze this routing table for Administrative Distance conflicts.

[Assistant]
<reasoning>
1. Observation: Network 10.4.253.0/24 appears in both OSPF (metric 15, AD 110) and EIGRP (metric 300850, AD 90). The metrics differ by 20056x, but EIGRP's lower AD (90 < 110) makes it the active route.
2. Analysis: OSPF and EIGRP use completely different metric scales. OSPF cost is based on cumulative link bandwidth (typically 1–65535), while EIGRP composite metric combines bandwidth, delay, load, and reliability (typically 100–10,000,000). Direct comparison is meaningless. However, the coexistence of both protocols for the same prefix indicates route redistribution or accidental dual-protocol deployment.
3. Context: If redistribution is intentional, metrics must be scaled appropriately (e.g., OSPF→EIGRP metric translation). If accidental, the protocols compete for RIB installation, causing route flapping if AD values are manipulated. The EIGRP path may be suboptimal despite lower AD if the OSPF path is actually better in terms of latency/hops.
4. Recommendation: Verify if dual-protocol learning is intentional. If redistributing, use route-maps with metric scaling (e.g., 'set metric 10000 100 255 1 1500' for EIGRP). If accidental, remove one protocol from the interface or use distribute-lists. Ensure AD values reflect true path preference—consider 'distance eigrp' or 'distance ospf' adjustments.
</reasoning>
<answer>
WARNING: Inconsistent metrics between protocols for 10.4.253.0/24. OSPF metric 15 vs EIGRP metric 300850 (different scales). EIGRP wins due to lower AD (90). Verify redistribution scaling or remove accidental dual-protocol deployment.
</answer>


[System] You are a network routing expert. Analyze the routing table, detect issues, and provide step-by-step reasoning. Use the format: <reasoning>...step-by-step analysis...</reasoning><answer>...concise answer...</answer>

[User]
Routing table:
O    10.226.72.0/16 [110/9] via 192.168.218.244, 05:46:25, GigabitEthernet3/0
O    10.43.2.0/24 [110/1940] via 192.168.177.115, 12:22:25, FastEthernet0/3
O    10.197.213.0/30 [110/19] via 192.168.195.144, 09:29:10, Port-channel5
O    10.90.10.0/30 [110/15] via 192.168.33.53, 14:15:11, Port-channel1
O    10.42.1.0/24 [110/5] via 192.168.63.74, 09:20:45, GigabitEthernet1/1
L    192.168.1.1/32 is directly connected, GigabitEthernet0/0
O    10.118.101.0/17 [110/10] via 192.168.76.125, 06:34:33, GigabitEthernet3/2
C    192.168.1.0/24 is directly connected, GigabitEthernet0/0
O    10.148.189.0/19 [110/14] via 192.168.145.5, 15:25:35, Loopback0
O    10.239.208.0/26 [110/4] via 192.168.23.198, 23:15:42, Serial0/0:0
O    10.97.190.0/29 [110/10] via 192.168.90.19, 02:28:42, Serial3/0:0

Question: Does this routing table have any routing inconsistencies?

[Assistant]
<reasoning>
1. Observation: Intra-area route 10.42.1.0/24 has metric 5, while inter-area route 10.43.2.0/24 has metric 1940. The inter-area metric is 1935 higher despite both destinations being roughly equidistant.
2. Analysis: OSPF inter-area routes are calculated as the sum of intra-area cost to the ABR plus the cost from ABR to destination. An abnormally high inter-area metric suggests: (a) suboptimal ABR placement, (b) a high-cost link in the backbone (Area 0), (c) virtual link with accumulated cost, or (d) summary LSA (Type 3) advertising a high metric from the ABR.
3. Context: Inter-area metric inconsistency causes suboptimal routing—traffic to 10.43.2.0/24 takes a much longer path than necessary. This can create asymmetric routing if return traffic takes a shorter intra-area path. It also complicates traffic engineering and SLA compliance.
4. Recommendation: Verify ABR placement and backbone topology. Check 'show ip ospf database summary' for the advertised metric of 10.43.2.0/24. Ensure virtual links (if used) are not adding excessive cost. Consider using 'area range' with 'cost' override on ABRs to normalize inter-area metrics. Verify all backbone links have consistent bandwidth settings.
</reasoning>
<answer>
WARNING: OSPF inter-area metric inconsistency. 10.43.2.0/24 metric 1940 is 1935 higher than intra-area 10.42.1.0/24 (5). Check ABR placement, backbone link costs, virtual links, and summary LSA metrics. Suboptimal routing likely.
</answer>


[System] You are a network routing expert. Analyze the routing table, detect issues, and provide step-by-step reasoning. Use the format: <reasoning>...step-by-step analysis...</reasoning><answer>...concise answer...</answer>

[User]
Routing table:
C    192.168.1.0/24 is directly connected, GigabitEthernet0/0
B    10.34.118.0/26 [20/13] via 192.168.129.12
B    10.204.41.0/19 [20/5] via 192.168.190.127
B    10.235.230.0/23 [20/12] via 192.168.197.50
B    10.236.155.0/20 [20/9] via 192.168.5.86
B    10.11.210.0/25 [20/6] via 192.168.146.41
B    10.139.113.0/27 [20/8] via 192.168.14.126
B    10.37.5.0/20 [20/13] via 192.168.139.20
B    10.181.223.0/27 [20/5] via 192.168.70.194
L    192.168.1.1/32 is directly connected, GigabitEthernet0/0
B    10.136.23.0/27 [20/5] via 192.168.193.95
B    10.215.109.0/20 [20/5] via 192.168.14.166
B    10.92.139.0/21 [20/8] via 192.168.222.20
B    10.107.126.0/17 [20/2] via 192.168.238.157
B    10.42.197.0/24 [20/1821] via 192.168.61.166

Question: Analyze this routing table for Administrative Distance conflicts.

[Assistant]
<reasoning>
1. Observation: BGP route to 10.42.197.0/24 has MED 1821, while all other BGP routes have MED between 0 and 15. The MED deviation is 121x to 1821x from the normal range.
2. Analysis: MED (Multi-Exit Discriminator) is used for inter-AS path selection when multiple paths exist from the same neighboring AS. A MED of 1821 is atypical—normal MED values reflect IGP cost (usually <1000). This extreme value suggests: (a) IGP metric redistribution without scaling, (b) manual MED policy misconfiguration, (c) AS-path prepending combined with MED, or (d) a BGP community setting MED incorrectly.
3. Context: BGP best-path selection compares MED after weight, local-preference, and AS-path length. An extreme MED makes this path the least preferred among equal AS-path alternatives, effectively black-holing traffic if it's the only path. It also complicates traffic engineering.
4. Recommendation: Verify MED configuration on the advertising router. Check route-maps setting MED based on IGP metric—consider dividing by a factor (e.g., 'set metric igp-cost / 10'). Review BGP communities that manipulate MED. Ensure consistent MED policy across all BGP speakers in the AS.
</reasoning>
<answer>
WARNING: BGP MED skew for 10.42.197.0/24. MED 1821 is 121x–1821x higher than normal (0–15). Check IGP redistribution scaling, route-map MED policies, and community configurations. Path likely depreferred.
</answer>


[System] You are a network routing expert. Analyze the routing table, detect issues, and provide step-by-step reasoning. Use the format: <reasoning>...step-by-step analysis...</reasoning><answer>...concise answer...</answer>

[User]
Routing table:
B    10.133.218.0/19 [20/3] via 192.168.167.178
B    10.92.25.0/21 [20/3] via 192.168.114.147
B    10.56.248.0/25 [20/7] via 192.168.166.86
B    10.116.220.0/30 [20/0] via 192.168.141.224
B    10.74.226.0/20 [20/9] via 192.168.118.95
B    10.239.127.0/16 [20/8] via 192.168.133.148
B    10.44.31.0/20 [20/10] via 192.168.161.115
B    10.13.236.0/26 [20/4] via 192.168.13.114
B    10.140.51.0/24 [20/2] via 192.168.92.13
C    192.168.1.0/24 is directly connected, GigabitEthernet0/0
B    10.21.245.0/24 [20/2] via 192.168.149.159
B    10.199.69.0/16 [20/8] via 192.168.212.216
B    10.177.203.0/16 [20/11] via 192.168.250.156
B    10.210.7.0/18 [20/6] via 192.168.61.184
L    192.168.1.1/32 is directly connected, GigabitEthernet0/0
B    10.21.245.0/24 [20/328] via 192.168.17.238

Question: Identify all potential issues in this routing table and classify them by severity.

[Assistant]
<reasoning>
1. Observation: Two BGP routes to 10.21.245.0/24 exist with oscillating MED values: 2 via 192.168.149.159 and 328 via 192.168.17.238. The MED difference of 326 causes repeated best-path changes.
2. Analysis: MED flapping between BGP peers indicates inconsistent IGP metric redistribution. Possible causes: (a) IGP metric changes on the path to the next-hop, (b) route-map applying MED based on a dynamic metric (e.g., delay, load), (c) dual-homed peers with different IGP costs, or (d) BGP policy oscillation between two route-maps.
3. Context: BGP best-path selection runs for each prefix when MED changes. With many prefixes, this causes CPU spikes and route churn. The router may also send repeated updates to downstream peers, amplifying the instability. MED oscillation is a known cause of BGP route dampening activation.
4. Recommendation: Stabilize the IGP metric to the BGP next-hop addresses. Use 'set metric' with a fixed value in route-maps instead of dynamic IGP-derived MED. Consider using 'bgp deterministic-med' to ensure consistent comparison. Implement BGP route dampening to suppress flapping prefixes. If using IGP-derived MED, ensure IGP is stable (e.g., OSPF cost not flapping).
</reasoning>
<answer>
WARNING: BGP MED flapping for 10.21.245.0/24. MED oscillates between 2 and 328. Check IGP metric stability, route-map MED policies, and 'bgp deterministic-med'. Implement BGP dampening. CPU impact from repeated best-path selection.
</answer>


[System] You are a network routing expert. Analyze the routing table, detect issues, and provide step-by-step reasoning. Use the format: <reasoning>...step-by-step analysis...</reasoning><answer>...concise answer...</answer>

[User]
Routing table:
O    10.97.12.0/28 [110/15] via 192.168.146.137, 18:13:50, GigabitEthernet2/0
O    10.153.117.0/16 [110/7] via 192.168.122.247, 02:29:56, FastEthernet0/2
O    10.185.77.0/30 [110/19] via 192.168.230.148, 18:03:02, GigabitEthernet1/0
O    10.84.152.0/29 [110/18] via 192.168.242.212, 05:21:24, FastEthernet3/3
L    192.168.1.1/32 is directly connected, GigabitEthernet0/0
O    10.111.99.0/21 [110/9] via 192.168.229.24, 11:26:55, Loopback79
O    10.40.1.0/24 [110/5] via 192.168.199.76, 21:02:15, Loopback72
O    10.48.135.0/16 [110/11] via 192.168.175.28, 13:42:37, Serial2/0:0
C    192.168.1.0/24 is directly connected, GigabitEthernet0/0
O    10.13.2.0/24 [110/1268] via 192.168.55.211, 13:52:26, FastEthernet1/3
O    10.229.50.0/28 [110/8] via 192.168.111.74, 18:03:47, FastEthernet3/1
O    10.210.129.0/26 [110/5] via 192.168.40.30, 09:18:39, Loopback75
O    10.111.7.0/17 [110/14] via 192.168.190.73, 11:02:02, Serial0/1:1

Question: Does this routing table have any routing inconsistencies?

[Assistant]
<reasoning>
1. Observation: Intra-area route 10.40.1.0/24 has metric 5, while inter-area route 10.13.2.0/24 has metric 1268. The inter-area metric is 1263 higher despite both destinations being roughly equidistant.
2. Analysis: OSPF inter-area routes are calculated as the sum of intra-area cost to the ABR plus the cost from ABR to destination. An abnormally high inter-area metric suggests: (a) suboptimal ABR placement, (b) a high-cost link in the backbone (Area 0), (c) virtual link with accumulated cost, or (d) summary LSA (Type 3) advertising a high metric from the ABR.
3. Context: Inter-area metric inconsistency causes suboptimal routing—traffic to 10.13.2.0/24 takes a much longer path than necessary. This can create asymmetric routing if return traffic takes a shorter intra-area path. It also complicates traffic engineering and SLA compliance.
4. Recommendation: Verify ABR placement and backbone topology. Check 'show ip ospf database summary' for the advertised metric of 10.13.2.0/24. Ensure virtual links (if used) are not adding excessive cost. Consider using 'area range' with 'cost' override on ABRs to normalize inter-area metrics. Verify all backbone links have consistent bandwidth settings.
</reasoning>
<answer>
WARNING: OSPF inter-area metric inconsistency. 10.13.2.0/24 metric 1268 is 1263 higher than intra-area 10.40.1.0/24 (5). Check ABR placement, backbone link costs, virtual links, and summary LSA metrics. Suboptimal routing likely.
</answer>