Okay, so most people configuring UCS are doing so with 10 Gbps links. Say, however, you are (not so) patiently waiting on budget approval for that 10 GB blade and you have a sad that your shiny UCS is collecting dust. Cheer up, my friend, you can use 1 Gbps connections to bring that chassis online.
When you initially insert your GLC-SX-MMD transceiver into your 6248 Fabric Interconnect, you are likely to see this rather unfriendly message*:
Fear not, your SFP is only in a failure state because you haven’t let UCS in on your brilliant plan to use lower speed links for the time being. You need to do this by clicking the Show Interface for the link in UCS Manager and selecting the 1 Gbps radio button. As you can see in the screen shot below, the default is 10 Gbps:
Once selected, the UCS will quit whining about so-called validation failures and let you configure the port and the port channel that will make your sys admin happy. Well, okay let’s be realistic, make your sys admin happier. Also, as a side note, be sure to use LACP in that port channel configuration, that is if you want it to actually work. Filing one that under lessons learned during this adventure as well…
*if you refer to the Data Sheet for the 6200 Series Fabric Interconnects found here you won’t see the GLC-SX-MMD listed. My VAR sent me over the screen shot below to assuage my fears after TAC initially told me the SFP wasn’t supported. I have yet to locate the original doc on Cisco’s website, if you have a link, please feel free to post it.