no ip classless utility

[ohassairi]

            Hi

i understand the difference between (ip classless) and (no ip classless)     but i wonder is there a senario where we may need the (no ip classless) command !

if no so why it exist? why we don't say that in all cases we are (ip classless)

thanks 

[Giuseppe Larosa]

Hello Ohassairi,

the command is probably still available for back compatibiilty purposes.

In the unlikely case that you need to mix old devices and new devices you have a chance to make new devices behave as the old ones.

However, since IOS 12.0 the ip classless is the default and so  it has been in the last 12-13 years!

In addition RIPv1 and IGRP the only classful routing protocols are obsolete.

Hope to help

Giuseppe