Techniques are described for avoiding traffic loss in a network when a designated router (DR) for a L2 broadcast communication domain loses its route toward a multicast traffic source. The disclosed techniques may be utilized in a scenario where a receiver is multi-homed to a DR network device and a non-DR network device by a L2 broadcast communication domain. Both the DR and the non-DR network devices receive a request from the receiver identifying a multicast group in which the receiver is interested. The non-DR network device monitors traffic injected into the L2 broadcast communication domain by the DR in order to determine whether the DR has lost the route to the source of the multicast group. If the DR has lost the route, the non-DR network device performs a repair by sending the multicast data traffic for the multicast group to the receiver on the L2 broadcast communication domain.