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Network L6 NETWORK-035 · 26 min

BGP session is established but the expected prefix never reaches the RIB

The neighbor shows Established, yet the target route is absent because a prefix list, route map, or best-path rule discards it before installation.

NetworkPlatform ReliabilityLevel 6Pro26 min
Scenario

The neighbor shows Established, yet the target route is absent because a prefix list, route map, or best-path rule discards it before installation.

What to check first
  • Identify the primary failure signal in the BGP Path Control scenario.
  • Separate visible symptoms from the underlying technical dependency.
  • Describe the safest recovery path and the follow-up prevention work.
Checking checklist
  1. Summarize the current impact and the last known change.
  2. Collect direct evidence from logs, runtime state, and configuration before changing anything.
  3. Separate immediate recovery from permanent prevention work.
Recovery and prevention

Choose the smallest safe recovery action first, then record the prevention work that reduces repeat incidents.

Questions worth viewing together
Why does an Established BGP session not guarantee route reachability?

Policy, best-path selection, and installation logic can still reject the route after the session itself is healthy.