Are there any static speed and duplex settings on the managment switch? The CIMC managment ports currently operate in auto mode for speed and duplex. If there is a mismatch on the managment switch this may be causing your problem.
I have this exact same problem also on our C240 M3 servers.
If I hook up dedicated CIMC port to our C2960S switch CIMC IP address is accessible for 30 seconds or so until it stops responding. Putting CIMC port on shutdown and then up state at switch end reset this issue and CIMC is again accessible for 30 secs or so until it goes dead again.
Once I configured CIMC access to be on shared LOM I can access CIMC OK, until shared LOM moves CIMC access to a ports which are configured for LACP and it stops working again. So not quite perfect situation for us.
I had support case open for this, but it did not resolve anything as access to a CIMC works if I connect my PC directly to a dedicated CIMC port. SR was 626466795 if any Cisco employees are interested in checking it up.
I think this problem is somehow related to our VLAN configuration on the switch end. We are running CIMC management access on VLAN 1 on the switch, I guess this is causing some kind STP loop or some else issue when dedicated CIMC port and shared LOMS are connected to a same switch. Although I cannot see any error messages related to this on the switch end. Once I have enough time, I will reconfigure our network to not use VLAN 1 and see if it has any change.
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==================== VIC FNIC driver does not support Virtual Volumes (
second level LUN ID ) An enhancement request has been created to track
this feature - CSCux64473 UPDATE - 12-14-2016 We made some traction on
the enhancement request - The Fix is in t...