Select one the the 2511 as your commserver.
Connect the console ports of the other routers to
the octal cable of the access server.
Give an IP address to the ethernet interface of the access server.
Configure the access server like:
line 1 16
no exec
transport input all
Then in order to access the router connected to the first port,
you have to do:
telnet ip 2001
ip = ethernet ip address.
To access the other routers,
telnet ip 200x
ip = ethernet ip address
x = port number