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.