Cisco Bug: CSCur47160 - CEF is showing Unresolved for BGP learned prefixes
Feb 11, 2018
- Cisco IOS
- Cisco ME 3600X-24TS-M Switch
- Cisco ME 3600X-24CX-M Switch
- Cisco ME 3600X-24FS-M Switch
- Cisco ME 3800X-24FS-M Switch Router
Known Affected Releases
Symptom: A forwarding decision may be stuck in an unresolved state, preventing traffic from flowing to one or more destinations. Conditions: This behaviour may be seen after BGP updates, usually of a temporary nature, that route a prefix such as A.B.C.0 through an unresolved next-hop A.B.C.D. This can create a loop. It may also be seen when default routes use an unattached next-hop prefix that is unresolved, creating another kind of loop. In some cases, even though there may be alternative paths that are not looped (eg: a looped repair path, but an unlooped primary path), the whole prefix is treated as looped, and thus unresolved. The command "show ip cef <address> internal" can show whether a prefix is "looped" and "unresolved".
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