Cisco 2811 router serial int config

ciscorouter

I use cisco 2811 router when I try to config s0/0/0 serial interface using (config)#int serial 0/0/0commond it says "%Invalid interface type and number" what's wrong with this commond?
Thanks

Best Answer

The router does not think it has an interface with that name run show ip int brief to get a list of interfaces present in the router

This may be of help.

Interface and Line Numbers in Cisco 1800, 2800 and 3800 Series Routers

www.cisco.com/en/US/products/hw/routers/ps282/products_tech_note09186a008035b051.shtml