Two cities have one NE80 respectively. Two NE80s are bound as one IP-Trunk interface through three 2.5G POS interfaces. ISIS routing protocol is run between two NE80s. IP-Trunk link is up and two devices can ping through interconnected interface, but ISIS neighbor relation cannot be built between NE80Es.
1. Carefully check ISIS configuration of two devices and they run on Level-2. ISIS is enabled on IP-Trunk interface and the configuration of two devices are not problematic.
2. Check device version of two NE80s and they are consistent. Enable ISIS on local NE80 and another NE40 and it is normal.
3. Two points pass transmission, but Active member of Trunk link is not consistent. Active member of one port is one and another is 2. Two NE80s can be pinged, but ISIS neighbor relation cannot be established. Change active member of IP-Trunk interface of two ports as 3 and ISIS is normally enabled.
1. ISIS configuration on two NE80s is not consistent.
2. The device version of two NE80s is not consistent and ISIS packet does not match.
3. The transmission link or IP-Trunk link is problematic.
Trunk link state is up, but Active member of two ports is not consistent. It is possible ping is normal, but the protocol is not reachable or parts of forwarding traffic is discarded. The reason is that member port of ping and that of protocol are not consistent.