Since there is very little out there on this, and since it caused plenty of heartache for me, I thought I’d write this up for those having issues with FCoE on the bigger Nexus 5k’s.

Apparently there is a bug feature in the 5548 / 5596 switch where they left out the default QoS policies.  Those have to be in place for FCoE to work.  So they’re shipping the switch with FCoE enabled, but this QoS policy is missing.

What results is once you get everything setup, you’ll see some FLOGI logins, but it’s very sporadic.  The logins will come in and out of the fabric, and no FCoE will happen.  Your FCoE adapters will report link down, even though the vfc’s are up, and the ethernet interfaces are up.

What I suspect is happening – and take this for what it’s worth from an expired CCNA – is the MTU isn’t set properly for the FCoE b/c the system QoS policies aren’t letting the switch know that there is FCoE.  It wasn’t until I mentioned that I changed the default MTU that the Cisco TAC level 2 guy finally remembered this little QoS problem with the big switches.

But he sent me the article, so I’ll save you some time.

If you copy the code in blue and paste it, your links will come up instantly and you’ll be ready to roll.  Here’s the link to the Cisco article.

The FCoE class-fcoe system class is not enabled in the QoS configuration.

Solution

For a Cisco Nexus 5548 switch, the FCoE class-fcoe system class is not enabled by default in the QoS configuration. Before enabling FCoE, you must include class-fcoe in each of the following policy types:

The FCoE class-fcoe system class is not enabled in the QoS configuration.

Solution

For a Cisco Nexus 5548 switch, the FCoE class-fcoe system class is not enabled by default in the QoS configuration. Before enabling FCoE, you must include class-fcoe in each of the following policy types:

•Network-QoS

•Queuing

•QoS

The following is an example of a service policy that needs to be configured:

F340.24.10-5548-1

class-map type qos class-fcoe 

class-map type queuing class-fcoe 

match qos-group 1 

class-map type queuing class-all-flood 

match qos-group 2 

class-map type queuing class-ip-multicast 

match qos-group 2 

class-map type network-qos class-fcoe 

match qos-group 1 

class-map type network-qos class-all-flood 

match qos-group 2 

class-map type network-qos class-ip-multicast 

match qos-group 2 

system qos 

 service-policy type qos input fcoe-default-in-policy 

 service-policy type queuing input fcoe-default-in-policy 

 service-policy type queuing output fcoe-default-out-policy

 service-policy type network-qos fcoe-default-nq-policy