Connecting a Catalyst 3560CX-8XPD-S switch to 1G optical network

[tehuti2016]

I’m trying to connect to the SFP+ with a 1G link. I’m using two identical Finisar FTLF8524P2BNV-EC SFP+ modules and a short optical cable. First, I connected the switch port to my Server and got no link (not even LEDs blinking on either side). Then I inserted the two SFP+ modules into both SFP+ ports and connected the cable. Still no LED blinking. To make sure I did the same with two 10G Finisar modules and the same optical cable - no problem. I took the two 1G modules and same cable to another 1G SFP+ switch and connected them – no problem.

Cisco documentation clearly says that my switch support 1G SFP+ modules. The Cisco compatibility list does not list any 3^rd party modules, only Cisco so this doesn’t help me too much…

Hope the Community can help me.

Thank you and Best regards,

Nir.

[Iulian Vaideanu]

I have no experience with 3560CX switches (do they take "service unsupported-transceiver"?) or with Multigigabit Ethernet (did you try "speed 1000"?), and also FTLF8524P2BNV looks pretty unusual (according to the datasheet it's rate selectable - 1/2/4 Gb/s Fibre Channel or 1000Base-SX Ethernet - but maybe the switch can't do the selection correctly), but maybe there's a simpler issue: is the optical cable multi-mode (usually orange, but I've seen blue or grey) or single-mode (yellow)?

https://www.finisar.com/sites/default/files/downloads/ftlf8524p2xny_4.25gbs_short-wavelength_sfp_transceiver_spec_revj.pdf

[tehuti2016]

I am using MM cable.

I did try other 1G modules from Intel, Avago, JDSU and PicoLight. Some are dual FC/Ethernet but some are Ethernet only. None were working.

Is there some setting I need to turn on to allow 3rd party modules?

I will try to find a Cisco branded 1G SFP module as [@p.dath]  proposed.

Thanks,

Nir.

[Iulian Vaideanu]

"service unsupported-transceiver" in global config (there will be a warning about no support if doing this);  also, "speed 1000" might be necessary under the interface config...

[tehuti2016]

I searched the software manual and there is no reference to the string "unsupported-transceiver".

I did find the "speed" command. Now I have to study how to use it. I'm a newbie to Cisco routers...

Thanks,

Nir.

[Iulian Vaideanu]

The "service unsupported-transceiver" command is indeed undocumented (it cannot even be auto-completed, you have to type the whole of it).

As for the "speed" command, just "conf t", "interface tex/y" (or whatever it's called on 3560CX), "speed 1000" - slide 11 of this presentation shows a list of available options for mgig ports:

http://www.slideshare.net/Cisco_Mobility/technical-overview-of-new-cisco-catalyst-multigigabit-switches

Or, even better, the Config Guide for your switch:

http://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst2960cx_3650cx/software/release/15-2_3_e/configuration/guide/b_1523e_consolidated_2960cx_3560cx_cg/Configuring_MultiGigabit_Ports_on_WS_C3560CX_8PD_S_.html

[tehuti2016]

Hi,

I'm unable for some reason to activate the "service" command. I tried it under the normal console and also under the "enable" mode without success:

I also tried the "speed" command. It doesn't take any value other than "nonegotiate" when a 1G module is inserted (The port is named Gi1/0/n):

When there is no module (the port is now named Te1/0/n), it can also take "10000" as a value:

I will add that when using a Cisco branded 1G transceiver, everything works and no configuration is required. The speed is automatically selected according to the module type.

Thanks,

Nir.

[Iulian Vaideanu · Accepted solution]

It's a config command, so first enter "enable" mode, then "configure terminal", then "service unsupported-transceiver".

[tehuti2016]

Oh. Stupid me. This Works!

Thank you so much!

Nir.

[norman.woeske@computacenter.co]

You saved my day :-) Thanks!

[Philip D'Ath · Accepted solution]

Unless you enjoy pain, no support from Cisco TAC, and wasting lots of time only use Cisco SFPs in Cisco switches.