Cisco Nexus 5548 SFP Validation Failed

During a recent Nexus deployment I came across a very small problem which was very easily solved.

When doing a sh int brief on the Nexus 5548 I saw the following

Eth1/17       1      eth  access down    SFP validation failed       10G(D) —
Eth1/18       1      eth  access down    SFP validation failed       10G(D) —

The SFP’s that are in these slots were DS-SFP-FC8G SW

The reason is that in a Nexus 5548 the ports can either run as Ethernet or Fiber Channel. The default configuration is Ethernet.  To change the mode of the port

NX5548-SW1# conf t
Enter configuration commands, one per line.  End with CNTL/Z.
NX5548-SW1(config)# slot 1
NX5548-SW1(config-slot)# port 25-32 type fc
NX5548-SW1(config-slot)# end
NX5548-SW1# copy run start
[########################################] 100%
NX5548-SW1# reload

The Cisco doc is here

www.cisco.com/en/US/docs/switches/datacenter/nexus5000/sw/release/notes/Rel_5_0_3_N1_1/Nexus5000

Once the switch has reloaded the ports now show as FC and up!

fc1/31     1      auto   on      up               swl    F       8    —
fc1/32     1      auto   on      up               swl    F       8    —

Another Reason

Another reason why you might see SFP Validation failed is you are inserting a 1G RJ45 SFP into a 10G SFP slot.

Hard Code the port to 1000 and the SFP will come online

Watch this blog over the next few months for more Nexus tips, the next challenge is FCOE to Netapp, I will also be pursuing the DCUFI certification.