CC13: The Global ASN on the Contrail Controllers intermittently resets to the default ASN

[Steven Sciriha]

Issue description:

It has been noted that the configured custom Global ASN on the Contrail Controllers (ex. 64870) intermittently resets to the default value of 64512 with no apparent trigger. This issue usually impacts a single Controller at a time though you can end up with multiple controllers in this state unless the workaround is applied in a timely manner.

Impact:

When this issue happens the Contrail Controllers (and DCGW) throw a BGP Peer mismatch error which then brings down the associated internal BGP peer session between the impacted Controller and the 2 DCGWs. If this issue is not addressed it can lead to an inconsistent routing state between the Overlay and Underlay/External networks as routes will not be advertised between the Controllers and the DGGWs.

Workaround:

When the issue is noted, update the ASN configuration manually for the impacted Controller/s using the Contrail WEB UI.

[Shivayogi Ugaji (shivayogi123)]

Sahil, can you take a look.