Symptom
Delay in the interface programming leading to slower convergence and possible traffic black-holing during the delay. Only occurs while the MAC Cache is being executed while the interface programming is occurring.
Conditions
MAC Cache (executed via "show l2vpn forwarding mac ..." or "show l2vpn forwarding bridge mac..." can slow the processing of interface programming events.
Workaround
Avoid exercising the MAC Cache (on-demand process administered by user) during transitions in the interface.
Further Problem Description
This was first observed while the MAC Cache was being executed by a script every couple of minutes while noisy optics lead to interface flaps. During the flaps blackholing was observed. This was later attributed to the delay in uidb updates due to MAC Cache processing.
