IOS XR ISIS losing adjacency periodically as a result even the physical interface directly connected to it's neighbour loses connectivity. However, the port status and protocol is up. Ping to the neighbour fails.
Error:
isis[1013]: %ROUTING-ISIS-6-ERR_DUPID : ISIS (LAB): Duplicate System ID 0100.6400.2100 already used by Local System detected in IIH received on GigabitEthernet0/0/0/6 SNPA ccb6.c8f6.c9e6
Have checked all routers the ISIS ID is unique and different on all the routers connected.
