Symptom
A route that is redistributed from OMP to BGP will have an incorrect AS_PATH attached to it. This can cause BGP Best-path resolution on later BGP hops that rely on AS_PATH as a tie breaker to make incorrect decisions. This in turn can lead to asymmetric/inefficient routing.
Conditions
* Multiple routes for the same prefix in OMP.
* The routes have different BGP paths (in content and/or length).
Workaround
Apply routing logic to other hops to ensure that AS_PATH length/content is not used as the tie breaker for BGP in later hops.
Possible Solutions include:
* Setting a local preference.
* Ensuring that OMP only installs certain routes in the routing table for redistribution.
* Ensuring that AS_PATH length is the same for all routes for that prefix.
Further Problem Description
When OMP is redistributing a prefix into BGP from multiple remote devices and all path attributes are equal, the tie breaker is the highest OMP system IP. This is seen as the next hop for the prefix added into the BGP table. However, because of this defect, the AS-Path installed for the prefix in BGP is coming from the lowest System IP.
