Cisco Bug: CSCtc58999 - Support for 16 import path in maximum-path command
Jan 31, 2014
- Cisco IOS
Known Affected Releases
Basic Description: Customer requests for increasing the limit on the paths that can be imported for 12.0(32)SY9 throttle. Without this fix, for the CLI "maximum-path import <number of paths>", limit is 8. This fix increases the limit to 16. Symptoms: ~90 sec outage during best path switchover even though there are multiple redundant backup paths available with their nexthops the same as the bestpath and "maximum-path import 8" is configured. 8 is the upper limit for this release and the expected outage is ~15 sec, not ~90 sec. Conditions: When redundant paths via multiple route-reflectors to the bestpath nexthop are available, the backup paths are utilized configuring "maximum-path import <number of paths>". Otherwise, if the best path goes away, it takes a while before the scanner runs and repopulate the VRFs with the backup paths (~90 sec). The multipath feature does not help because the nexthop addresses are identical. However, when the import limit is 8 while the number of backup paths is more than 8, due to the non-deterministic nature of the import of the backup paths, there is no guarantee that the backup path with the highest preference will be among the paths that have been imported. If it is not, configuring "maximum-paths import 8" does not help reducing the downtime to ~15 sec..
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