Topology: NE40----2500 + transmission----2500 + transmission ----NE40
Two FEs of NE40 act as eth-trunk and one-way is reachable.
1. NE40 configuration is not problematic.
2. 2500 + does not support eth-trunk binding. After NE40 FE binds, it has only one MAC address. 2500 + can only recognize one of bound FE port. 2500 + does not support binding and one-way is reachable. NE40 cancels trunk binding.
1. Two FEs of NE40 act as eth-trunk . Cable or configuration is problematic.
2. The transmission is problematic.