I recently had a issue during an FSM install. For 3 days we could not get networking on ETH1.
The first vendor had given up and used a single network for data and management using ETH0 which routes through the CMM. However, this networking schema does not allow the FSM to use a 10GB network but more importantly it does not allow for management deeper into the systems and some more of the advanced functions that the FSM provides.
To make a long story short I worked with support for those 3 long days and it was determined by LEVEL 3 (product engineers) that we had a bad NIC and requested a replacement. I had brought my own FSM with me and after a rebuild of that it was still having the issue so I dug further and noticed that VLAN tagging was enabled for the internal switch-port INTA1. THIS IS NOT CORRECT!!
Since the FSM setup does not allow for configuration of a VLAN you must have VLAN tagging DISABLED and the customers VLAN defined on the switch-port the FSM is on
(in my case INTA1). Once disabled we were able to get network immediately and ping the customers gateway.
WHAT A NIGHTMARE.