[c-nsp] SFP module on 2921 ISR router

[Nick Hilliard]

On 06/06/2011 17:35, K bharathan wrote:
> hi
> i'm trying to use a 1000base SFP module in cisco 2921 ISR ; on the router
> SFP appears to be assigned to G0/1; but when i put a SFP-LX-SM module
> nothing happens; no lights no connectivity and int is not coming up; is
> there any configuration required to make fibre port identified
> the following are given as certifed in a cisco doc
> GLC-LH-SM= 1000Base-LX/LH 9/125 1310 Single 10 km
> GLC-ZX-SM= 1000Base-ZX 9/125 1550 Single 100 km
> CWDM-SFP-1470= 1000Base-CWDM 50 1470 Single 100 km
>
> currently i'm using a converter (by TRANSITION Networks) (the SFP module in
> this converter shows long range 20km)
> which SFP module i can use?

You can use a GLC-LH-SM.  This module (in fact, range of modules) does not 
support DOM.

As you correctly note, only the GLC-* SFPs are supported on this device:

> http://www.cisco.com/en/US/docs/interfaces_modules/transceiver_modules/compatibility/matrix/OL_6981.html#wp131775

Apparently, it is too much to expect Cisco to support their own transceivers.

You could try "service unsupported-transceiver" in your configuration.  It 
might work, or it might not - seemingly on newer code trains these days, it 
doesn't work as well as it used to.

Alternatively, get yourself a third party GLC-LH-SM from a reputable 
dealer.  There are lots of knock-offs available in the grey market, many of 
which are complete trash, and some of which are really good quality units.

Nick