I have a customer who has a large network spread over several sites across the uk. the network addresses are ***.***.155.1 & ***.***.161.1

The system is on 161.50, I can ping it locally and all is ok, however i cannot ping it from 155.1. I can ping 161.100 (laptop) from 155.1 and vise versa.

I can use manager from 161.100 but not 155.1, any ideas