IOM failover interrupted

[ankur55800]

Hi,

Can someone explain to me, IOM will failover or not if any one of the l1 and l2 cables of FI is down.?

Thanks

[Riaan van Niekerk]

The L1/L2 cables for the interconnect are configured for redundancy. If one link goes down, communication between FIs will happen on the remaining uplink.

What do you mean by IOM failover?

[Steven Tardy · Accepted solution]

It is a common misunderstanding that the UCS FI L1/L2 ports carry data plane traffic.
UCS FI L1/L2 ONLY carry FI cluster synchronization traffic and FI cluster heartbeat traffic.
Can't tell from your question if you think traffic through a failed IOM should cross the L1/L2 ports.

Under the hood the UCS FI L1/L2 ports are part of a network bond/team group.
If either L1 or L2 are down, then the UCS FI cluster behaves normally as the bond/team is still functional.
Anything that would happen with both L1 and L2 should happen with only L1 or L2.

IOM failover isn't really a thing.
Each IOM operates (mostly) independently.
Data plane traffic through each IOM is (or should be) configured to be redundant via UCS policy such that if one IOM fails, then traffic is sent through the remaining IOM.

Maybe you are asking about UCS Fabric Failover (the "Enable Failover" checkbox on a vNIC)?
UCS Fabric Failover should not be impacted by either L1 or L2 being down.
UCS Fabric Failover is controlled by the FI and not the IOM.