Cisco Bug: CSCvu79503 - Traffic black-holing due to routes missing in RIB
Aug 26, 2020
- Cisco Nexus 9000 Series Switches
Known Affected Releases
Symptom: Summary of symptoms: After continuous route flap in high prefix scale, BGP does not install some routes in URIB. Detailed symptoms: 1. BGP routes reachable via a particular RNH (lets say e.f.g.h/n) are not installed in URIB. 2. All BGP routes with that particular RNH are marked invalid with "inaccessible nexthop" reason in BGP table. 3. URIB throws the following message: %URIB-3-ADD_RPATH: urib [xxxxx] (default-base) Client "bgp-yyyyy" added a.b.c.d/n via not found rnh e.f.g.h/n%default 4. Route for RNH not present for recursive next-hop RIB confirmed using below command: # sh routing recursive-next-hop e.f.g.h/n IP Recursive Next-Hop Table for VRF "xxxxx" Virtual next-hop not found <<< Nothing here Conditions: 1. BGP prefix scale exceeding 100,000. 2. All these routes are continuously flapped, leading to BGP continuously installing and removing these routes in URIB over and over.
Bug details contain sensitive information and therefore require a Cisco.com account to be viewed.
Bug Details Include
- Full Description (including symptoms, conditions and workarounds)
- Known Fixed Releases
- Related Community Discussions
- Number of Related Support Cases