Cisco 871 Router: Quickly Change the ISP

Putty into the 871 Router

Run the command “Show Run” to start scrolling through and get the outside IP Interface, IP Address and Subnet Mask.

interface FastEthernet4
ip address %CurrentIPAddress% %CurrentIPSubnet%
!

Scroll further and get the IP Route (Gateway Address)

ip route 0.0.0.0 0.0.0.0 %CurrentGatewayIP%

Prpare a short script to remove the old ISP settings and add the new ISP settings.
Start with the Gateway (IP ROUTE).
Example below between the hypens.e

no ip route 0.0.0.0 0.0.0.0 %CurrentGatewayIP%
ip route 0.0.0.0 0.0.0.0 %NewGatewayIP%

interface FastEthernet4
no ip address %CurrentIPAddress%  %CurrentIPSubnet%
ip address %NewIPAddress% %NewIpAddressSubnet%
!
Run the command “Conf T

Copy and paste entire script into Putty.

Once internet is verified up and running, “Exit” out of Config mode.

Run the command “Write Mem

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