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.
I'm running into something similar.
We just put in new 4451 routers with GLC-SX-MM Part # 30-1301-03 (SFP's)
and we're trying to connect to a new 4507R+E 10gig Module using SFP-10G-SR Part#10-2415-03.
When we plug in the new cable we get no link light on the 4507 and are unable to ping between the two devices. I've been told you can't connect a 1Gig SFP to a 10Gig SFP, so we're trying to decipher the truth of this matter as we'd prefer fiber vs. copper.
Thanks for any suggestions!
The SFP-10G-SR operates via multimode, as does the GLC-SX-MM. It's not the coherent laser (singlemode fiber or SMF) vs. incoherent VCSEL or LED (multimode fiber MMF) light - it's the frequency that doesn' t match.
For anybody who's interested, have a look at this reference on SMF vs. MMF.
No. Wrong laser type.
Use a SFP that is compatible with singlemode fiber (SMF), per the attached data sheet:
according Q&A the Cisco catalyst 2960 -X and -S, the SFP+ can support both speed 10Gbps and 1Gbps but not lower
Q. Can the 10 Gigabit SFP+ slots on the Cisco Catalyst 2960-X model support 1 Gigabit SFP modules?
An SFP+ slot is compatible with an SFP transceiver. In that case it is acting effectively as an SFP slot. Kind of like an old blade in a 6509 only using half of the backplane fabric.
That's different than the case of an SFP+ 10 Gbps transceiver operating at 1 Gbps. That's what will not work.