Why Is My SFP Not Working?

Tom Hollingsworth shares his frustration at non-support of third-party interface modules (SFPs, as Tom calls them). If you try to use a non-vendor device, the switch will spit out an error and refuse to support it.

Why do vendors do this? Some claim it’s vendor lock in. You are stuck ordering your modules from the vendor at an inflated cost instead of buying them from a different source. Others claim it’s to help TAC troubleshoot the switch better in case of a failure. Still others say that it’s because the manufacturing tolerances on the vendor SFPs is much better than the third party offerings, even from the same OEM. I don’t have the answer, but I can tell you that Cisco, HP, Dell, and many others do this all the time.

Tom goes on to present a simple workaround, using undocumented Cisco commands, to force the switch to use these devices anyway. Read the whole thing at  The Networking Nerd.

About the author

Stephen Foskett

Stephen Foskett is an active participant in the world of enterprise information technology, currently focusing on enterprise storage, server virtualization, networking, and cloud computing. He organizes the popular Tech Field Day event series for Gestalt IT and runs Foskett Services. A long-time voice in the storage industry, Stephen has authored numerous articles for industry publications, and is a popular presenter at industry events. He can be found online at,, and on Twitter at @SFoskett.

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