Cisco 2950 Switch replacement problem

[budman007]

I have a Cisco 2950 switch with a dead fan in it. I am replacing with another Cisco 2950 switch. Both are 24 port switches. The difference is, the old switch has built in Gigabit fibre ports(25&26), that fibre goes from the fibre box directly into the switch using a SC to ST fibre patch cable. The new switch has Gigabit fibre ports(25&26), but it requries the GBIC cards to plug the SC to SC fibre patch cable to work. My problem is this: When I plug the SC from he the Fibre box to the new GBIC Switch, I get no data light, period. I have tried swapping switches, gbic cards, sc-sc cables, etc. The output from the fibre box is good and working now, so I know the fibre isn't bad. I am using the same two fibre strands from the fibre box to the new switch, just with a sc-sc cable because a sc-st is now being used. What am I missing?

Thanks!           

[budman007]

The fiber that runs to this switch comes from a Cisco 2950EI model that has the same LX GBIC as the new switch. I even took out one of the GBIC in the new one and swapped it with the switch that runs to the old switch and the old switch still worked fine, but when I plug in the new switch, no lights, nothing.

I understand the wavelength is difference from FE vs GE, but does this mean the fiber box will only work with FE and not GE?

[aukhadiev]

Hi, Dale Brown...

As you wrote earlier (at 19.09.2013 13:17)

"The old switch is WS-C2955C-24. The new one is WS-C2950G-24-EI"

According this article:

http://www.cisco.com/en/US/products/hw/switches/ps700/products_tech_note09186a00800a7af7.shtml#cat2950

WS-C2950C-24 has  24 10/100 Ethernet ports and 2 100BASE-FX ports (100 Mbps)

WS-C2950G-24-EI has 24 10/100 Ethernet ports and 2 GBIC module slots

But the GBIC-module ports support only 1000 Mbps. The speed values of 10 Mbps and 100 Mbps are not supported...

[budman007]

Ok, the Gbic only will support 1000mbps, makes sense, so what would have to be changed? Replacing Switch and Fiber cable from the fiber box to the new switch. Before the fiber box, it comes from another 2950 that is 24EI,

[aukhadiev]

Dale, the old switch is WS-C2955C-24 and has 100BASE-FX fiber ports working at 100 Mbps, so i think at the other end of the optical cable the equipment is also only supports 100 Mpbs...

You can tell what kind of equipment (switch) at the other end of the optical cable?

[pieterh]

as SFP you have got the option:

GLC-GE-100FX              100BASE-FX SFP module for Gigabit Ethernet ports, 1310 nm wavelength, 2 km over MMF¹

Here the SFP does the speed conversion (Gig port 100M Fiber)

according to table-6 in

http://www.cisco.com/en/US/docs/routers/7200/install_and_upgrade/gbic_sfp_modules_install/5067g.html

This should also exist as GBIC.