I understand that the NM-1FE Fastethernet modules are not compatible with Cisco 2600 series routers, just the Ethernet 1-E module. With that being said, are there ANY modules supported by the 2600, 2621 or 2621XM series routers that have fastethernet port(s) outside of the pricey NM-16ESW module? I don't need a 16 port module!
I think you would spend less and get better results replacing that 16-years old model with it e.g. an 851, or 871. These have FE, almost current IOS, and much better performances.