c одной стороны
cat-r23#sh udld neighbors
Port     Device Name   Device ID     Port ID    Neighbor State
----     -----------   ---------     -------    --------------
Gi0/14   FOC1437X3WC     1            Gi0/1      Bidirectional

с другой
cat-r194#sh udld neighbors
Port     Device Name   Device ID     Port ID    Neighbor State
----     -----------   ---------     -------    --------------
Gi0/1    FOC1434V51M     1            Gi0/14     Bidirectional