today i use the SFP+ "SFP-10G-SR" in Cisco Catalyst 2960S-48TD-L connect to 1000BASE-SX SFP in 6509's module WS-X6724-SFP.
the port setting is trunk,but they don't work, even the led don't flush. then i also use the 1000BASE-SX SFP to replace SFP+ SFP-10G-SR in
2960S-48TD-L, then they cany working.
i look up the cisco data sheet , there are no data sheet to satament the 10G sfp+ can't down support 1G sfp. so i want to confirm the problem.
otherwise, the 10 SFP+ only can use for 10G SFP+ ; can't down suport 1G SFP.
this means: if you want to use the 10G SFP+ the other old device also need to replace.
thanks~for your help!!
Solved! Go to Solution.
Not entirely true. On Nexus I'm using the 10G twinax running at 1G. I used the "service unsupported-transceiver" command on the interface and it came right up. So far no issues. I know this isnt fiber so it may not apply.
In my case this was a quick fix because no RJ45 1G SFP's were on hand but there were excess twinax cables available. We are ordering those now. Other than support issues, if they work I dont see why we shouldnt use them.
We have Cisco core and edge switches with SFP-10G-SR-S connected with an OM3 fiber backbone. We are experiencing an issue that the link will run only if an OM3 patch cord is used to patch the sfp to the backbone fiber panel. The link won't come up if we patch it with an OM2 patch cord. Is there any technical reason for this failure?
You don't need to look only to the length of the OM2 patch cable, but to the entire link length.
OM2 has bandwidth 500. Max distance in 10 gbps is 82 m
OM3 has bandwidth 1500. Max distance in 10 gbps is 300 m
So your relatively short OM2 patch cord kills the link ( not enough fiber budget left over to reach the end of the entire link ) ...