[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    10.1.56.0/24 [110/5] via 192.168.217.27, 11:55:52, Serial0/1:1
C    192.168.1.0/24 is directly connected, GigabitEthernet0/0
O    10.47.234.0/26 [110/4] via 192.168.183.218, 06:27:52, Port-channel7
O    10.1.59.0/24 [110/10] via 192.168.143.153, 09:36:17, FastEthernet2/2
O    10.48.69.0/28 [110/3] via 192.168.210.236, 04:45:20, Serial1/0:0
O    10.126.201.0/23 [110/10] via 192.168.72.148, 14:04:40, Loopback48
O    10.1.57.0/24 [110/3] via 192.168.44.113, 22:39:40, FastEthernet1/2
O    10.47.206.0/24 [110/13] via 192.168.142.178, 10:37:00, Loopback62
O    10.1.58.0/24 [110/4] via 192.168.219.43, 18:22:34, FastEthernet1/0

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

[Assistant]
<reasoning>
1. Observation: Four contiguous /24 networks (10.1.56.0/24, 10.1.57.0/24, 10.1.58.0/24, 10.1.59.0/24) are individually present in the routing table.
2. Analysis: These networks are sequential and could be summarized into a single /22 route (10.1.56.0/22), reducing routing table size by 75% for this block.
3. Context: Under-summarization bloats the routing table, increases memory usage, slows convergence, and increases CPU processing for route lookups. It also increases the size of routing updates sent to neighbors.
4. Recommendation: Configure route summarization on the ABR or ASBR to advertise 10.1.56.0/22 instead of the four individual /24 routes. This will improve scalability and convergence time.
</reasoning>
<answer>
INFO: Under-summarization detected. Four contiguous /24 routes (10.1.56.0/24 - 10.1.59.0/24) could be summarized as 10.1.56.0/22. Configure summarization to reduce routing table size and improve convergence.
</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    10.228.76.0/16 [110/11] via 192.168.125.166, 17:30:03, Loopback52
O    10.221.202.0/23 [110/15] via 192.168.15.98, 05:17:17, FastEthernet2/1
O    10.65.47.0/30 [110/3] via 192.168.169.32, 05:59:36, Loopback6
O    10.9.195.0/28 [110/19] via 192.168.183.123, 18:32:20, Loopback44
C    192.168.1.0/24 is directly connected, GigabitEthernet0/0
S    10.4.113.0/24 [1/0] via 192.168.9.1
O    10.4.113.0/24 [110/14] via 192.168.63.1, 00:04:12, Serial0/1:0
O    10.44.143.0/22 [110/8] via 192.168.70.108, 20:51:34, Port-channel4

Question: Analyze this routing table for Administrative Distance conflicts.

[Assistant]
<reasoning>
1. Observation: Network 10.4.113.0/24 appears in the routing table via two protocols: static (AD=1) via 192.168.9.1 and OSPF (AD=110) via 192.168.63.1.
2. Analysis: The static route has lower AD (1 vs 110), so it is the active route. However, if the static route's next-hop becomes unreachable, the OSPF route would take over. This dual-learning indicates a potential redistribution issue or accidental static route injection.
3. Context: AD conflicts can cause route flapping if the static route's next-hop is intermittently reachable. The router may oscillate between the static and OSPF paths, causing instability.
4. Recommendation: Verify if the static route is intentional. If OSPF should be the primary path, remove the static route or increase its AD (floating static). If the static route is required, ensure the next-hop is stable.
</reasoning>
<answer>
WARNING: AD conflict for 10.4.113.0/24. Static route (AD=1) via 192.168.9.1 overrides OSPF (AD=110) via 192.168.63.1. Verify if static route is intentional. Risk of route flapping if next-hop becomes unstable. Consider floating static with higher AD.
</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    10.141.215.0/20 [110/4] via 192.168.247.201, 19:39:12, Serial2/0:1
O    10.197.6.0/20 [110/4] via 192.168.211.100, 18:33:10, Port-channel4
O    10.194.86.0/18 [110/10] via 192.168.137.78, 02:10:27, Loopback18
O    10.1.1.0/24 [110/6] via 192.168.184.195, 05:27:28, GigabitEthernet1/0
S    10.6.0.0/16 [1/0] via 192.168.29.1
C    192.168.1.0/24 is directly connected, GigabitEthernet0/0
O    10.20.2.0/24 [110/2] via 192.168.208.27, 19:38:50, GigabitEthernet2/0

Question: Does this routing table have any routing inconsistencies?

[Assistant]
<reasoning>
1. Observation: A static summary route 10.6.0.0/16 is configured, but only specific subnets (10.1.1.0/24, 10.20.2.0/24) actually exist in the routing table.
2. Analysis: The /16 summary encompasses 256 /24 networks, but only a few are present. This is over-summarization, which will attract traffic for non-existent subnets and cause black-holed packets.
3. Context: Routers forwarding to this summary will send traffic for any 10.x.y.z destination within the /16, even for networks that don't exist. This wastes bandwidth and causes unnecessary processing.
4. Recommendation: Use a more specific summary (e.g., /20 or /22) that only covers existing subnets, or configure null0 routing with proper discard handling. Verify which subnets actually need to be advertised.
</reasoning>
<answer>
WARNING: Over-summarization detected. Static route 10.6.0.0/16 covers 256 subnets but only 2 exist. Traffic to non-existent subnets will be black-holed. Use a more specific summary or configure null0 discard.
</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    10.199.10.0/29 [110/2] via 192.168.194.123, 17:47:47, Serial2/1:1
O    10.79.39.0/24 [110/5] via 192.168.69.1, 00:00:55, Serial0/0:0
C    192.168.1.0/24 is directly connected, GigabitEthernet0/0
O    10.112.249.0/19 [110/17] via 192.168.139.112, 21:43:51, GigabitEthernet3/2
O    10.79.39.0/24 [110/5] via 192.168.46.1, 14:44:09, FastEthernet2/2
O    10.32.212.0/22 [110/16] via 192.168.169.139, 06:53:26, Loopback7

Question: Does this routing table have any routing inconsistencies?

[Assistant]
<reasoning>
1. Observation: Two ECMP OSPF routes exist for 10.79.39.0/24 with equal metrics (5) but vastly different ages: one is 14:44:09 old, the other is 00:00:55 old.
2. Analysis: The stale route (14:44:09) has not been refreshed, suggesting the neighbor may be down or the LSA has not been updated. OSPF should have removed this route if the neighbor is truly unreachable.
3. Context: A stale ECMP path can lead to black-holed traffic if the next-hop is actually unreachable but the route remains in the RIB. This indicates potential OSPF neighbor instability or timer misconfiguration.
4. Recommendation: Verify OSPF neighbor adjacency on FastEthernet2/2. Check for interface flaps or LSA refresh issues. Consider adjusting OSPF dead/hello timers.
</reasoning>
<answer>
WARNING: Stale ECMP path detected for 10.79.39.0/24. Route via 192.168.46.1 is 14:44:09 old while route via 192.168.69.1 is 00:00:55 old. Verify OSPF neighbor adjacency on FastEthernet2/2. Potential black-hole risk.
</answer>