IP classless command on Old Cisco 775 Router Configuration

[Doozer1]

Hello,

I need to know what command and where to use the command to make a 775 router not use Classfull routing. In an 1603 router the command is "ip classless" I dont beleive this works on an 775.

These routers are not IOS based & i cannot fiugre out how to do this.

Thanks for your help

Lee.

 

[loopback0]

Hello Lee,

From what I can remember as this is now an end of life router, you can not enable IP classless, but then again why would you need it. The 775 is a SOHO ( Small Office Home Office Router) normally you set up a default route out of your ISDN Interface to a central site or perhaps to the internet if you are using ISDN dialup.

not having IP classless will not prevent you doing something like having 172.16.1.0 255.255.255.0 on your LAN

ip classless is used as below


172.16.1.0---------R1---10.0.0.0----------R2----172.16.2.0

Without ip classless the 172.16.0.0 net is separated by the 10.0.0.0 net. With classful routing protocols like RIP version 1 R1 would never forward traffic to R2 for 172.16.2.0 a sit believes all of the 172.160.0.0 net is directly connected.

With IP classless if the router has a gateway of last resort or default route via the 10.0.0.0 network R1 will forward the unkown subnet to R2.


However with the 775 you would probably have this.

192.168.1.0/24--LAN--775router---------->0.0.0.0rest of the world

Therefore IP classless should not be an issue in an environment for which the 775 was designed.

Hope this helps