
NE40E-1 and NE40E-2 connect with each other with port Eth-Trunk 10. BFD for OSPF not work well on Eth-Trunk interface, when one of member port down, OSPF peer rebuild.


1. Check the parameter of BFD for OSPF. The detect RX interval and TX interval use default parameter, by default, the interval is 10ms.
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ospf 1 router-id 10.159.240.147
bfd all-interfaces enable
area 0.0.0.0
network 12.1.1.0 0.0.0.3
#
#
ospf 1 router-id 10.159.240.148
bfd all-interfaces enable
area 0.0.0.0
network 12.1.1.0 0.0.0.3
#
2. When shutdown one of memeber port of Eth-Trunk, the BFD state down and the OSPF peer rebuild.

The root cause is that the detect down performance of Eth-Trunk is 50ms on NE40E router. But the detect down interval of BFD is 10ms * 3 by default. When one of member port down, the BFD data still send to the port witch already been shutdown.

The solution:
1. When the cable is RJ45, configure the BFD RX and TX interval more than 500ms.
2. When the cable is fiber, configure the BFD RX and TX interval more than 100ms.
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ospf 1 router-id 10.159.240.147
bfd all-interfaces enable
bfd all-interfaces min-tx-interval 100 min-rx-interval 100
area 0.0.0.0
network 12.1.1.0 0.0.0.3
#