Description

If the bundle interface flaps as cHDLC MA is resyncing, then the cHDLC does not send a DPC to the platform, which means that traffic will not be forwarded on the bundle. For instance, this can occur if a bundle flaps during RP failover.

Symptom

All traffic using the bundle interface will be dropped, "show interfaces" will show the line protocol state as UP, but "show chdlc interfaces" will show it as DOWN.

Conditions

This is a corner case that has only been seen once, and can only occur on bundle interfaces if a bundle interface flaps during resync. Present in all releases prior to 3.9.1

Workaround

Restart the chdlc_ma process on RP to fully recover

Further Problem Description