In the simplest terms, one carries a mask (RIP 2, the classless) and one dosen't. If it has a mask, the router knows which part of address is network and which is host. Also, the classful protocol has to rely on the class of the protocol (A, B, C, D, E) to derive the network and host, unless the router has an interface attached to a subnetted network. The best book to learn this is CCIE Practical Studies, Vol 1, as the author does a good job explaining it.
Also classless and classful protocols look up routes in the rouing table differently. A classless use the longest match (most subnet bits in mask) to determine best route to destination and the classfull looks up by major network first, then works it's way down til it finds the best match. Also with classless, you can use "ip route 0.0.0.0 0.0.0.0" to create a gateway of last resort. -- RFC 1149 Compliant. Get in my head: http://sar.dynu.com ""Matt Saunders"" wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > Hi Group, > > Im really struggling to understand the requirement in using the ip classless > command when you are configuring a default route. > > I noticed that RIP 2 is a classless protocol & RIP ver 1 is a classfull. > > Can anyone help me understand what the difference is (in simple terms!!) as > i want to move on with my studies though im sure this is something thats > going to come up again!!!! > > Cheers > > Matt Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=38862&t=38862 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]