Huawei Huawei Huawei In [EVPN], in the DF re-election transient period, due to Ethernet Segment route transmission timer and timer clock discrepancy on each PEs, dual DF PEs will co-exist, traffic loop and disruption will be incurred. In MHN case, the consequences are particularly serious. Handshaking mechanism for DF election is introduced in this draft to resolve the problem.