How do you get a serial interface and line protocol to be up on a cisco router?

by admin on December 10, 2009


I have two cisco routers connected with serial cables and they are being configured with a console cable. I set the ip address of both routers 192.168.1.1 255.255.255.0 192.168.2.1 255.255.255.0 and then run a no shut. I exit to exec mode and run a show interface and all I get is Serial is up, line protocol is down. How do I get the line protocol to also be up?

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tast_the_wine December 10, 2009 at 10:51 am

Your IP address are in a different address range. The address you need are:

192.168.1.1 255.255.255.0 and on the other is, 192.168.1.2 255.255.255.0
That makes 256 – 2 = 254 hosts in this range.

Remember a class A is net.host.host.host
class B is net.net.host.host
class C is net.net.net.host

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