KB 95

How does one change the internal IP address of the Cisco 675 router?

Article:95
Created:2002-02-12 12:11:37
Categories:
  routing
  DSL

Question or Symptom

DO NOT USE THIS CONFIGURATION IF YOU HAVE A STATIC SUBNET INSTEAD SEE KNOWLEDGEBASE ARTICLE #104 In more cases than not people will have a numbering scheme for there network that doesn't follow the default that is set up in the Cisco Router. The Cisco 675's default intenal address is 10.0.0.1. Either a computer on someone's network already has that address, or they are using a totally different subnet.

Resolution

First you want to log into the router, then you want to go into enable mode by typing in:

enable

At that point it will ask you for the 'enable' password.

The command to change the ip address is:

set int eth0 address <ip address>

For example:

set int eth0 address 192.168.0.1

The Cisco 675 assumes a netmask of 255.255.255.0. If you need to set a different netmask the command is as follows:

set int eth0 netmask <netmask number>

For example:

set int eth0 netmask 255.255.255.252

Once you do that then type the following commands:

write reboot

(Big warning: don't use the subnet of 10.0.1.0. I had tried using it on our and a customer's router, and it would not route internet packets from the internal network to the external network. The Cisco 675 could ping the outside world, and the computers on the internal network would ping the Cisco 675, however, the computers on the internal network could not ping the outside world.)

Related KB articles

 KB 81 How do I configure my Cisco 675 or 678 for Megabit service?

 KB 94 How does one set up port forwarding on the Cisco 675 router?