This is probably something simple, but here goes 
I've got two cisco routers (2503 and 2504) that are connected back to back by a serial cable and have connectivity.
I want to upgrade the ios on the 2504 but i dont have a token ring network card, i've been looking at this guide:
http://www.cisco.com/en/US/products/hw/routers/ps233/products_tech_note09186a00800a6744.shtml
When i try and set the 2503 as a tftp server, i just get command not retained.
Anyone got any ideas on this?

I've got two cisco routers (2503 and 2504) that are connected back to back by a serial cable and have connectivity.
I want to upgrade the ios on the 2504 but i dont have a token ring network card, i've been looking at this guide:
http://www.cisco.com/en/US/products/hw/routers/ps233/products_tech_note09186a00800a6744.shtml
When i try and set the 2503 as a tftp server, i just get command not retained.
Anyone got any ideas on this?