Symptom

Connected route is not advertised after disabling BGP best external.

Conditions

The problem happens when CE advertises the connected route and PE is redistributing the same connected route. In such a case BGP picks the redistributed route as best path and incorrectly marks the CE path as Best external. When best-external configuration is removed, BGP tries to withdraw the CE path but withdraw will actually remove the bestpath from the peers.

Workaround

Don't remove best-external configuration or stop redistributing the connected route. Recovery: Clear the bgp PE peers which will readvertise the paths.

Further Problem Description