release-20.1:Backport!3734

Merged Andrey Vertiprahov requested to merge cherry-pick-1a455a29 into release-20.1

Generic.get_mac_address_table. Skip unknown interfaces.

See merge request !3734 (merged)

(cherry picked from commit 1a455a29)

45cc43c8 Generic.get_mac_address_table. Skip unknown interfaces.

Merge request reports