t will still advertise 10.0.0.0/8, just like RIPv1. The first thing you should do when configuring RIPv2 is turn off auto-summarization with the router command no auto-summary: R3 (config)# router rip R3 (config-router)# no auto-summary The routing table in a Cisco router makes no distinction between RIPv1 and RIPv2. Both protocols are represented by a single R in the routing table. Chapter 10: Routing Protocols EIGRP The Enhanced Internal Gateway Routing Protocol (EIGRP) is a classless enhancement to the Internal Gateway Routing Protocol (IGRP), which supported only classful net- works. EIGRP, like IGRP, is a Cisco-proprietary routing protocol, which means that only Cisco routers can use this protocol. If you throw a Juniper or Nortel router into your network, it will not be able to communicate with your Cisco routers using EIGRP. EIGRP is a very popular routing protocol because it's easy to configure and manage. With minimal configuration and design, you can get an EIGRP network up and run- ning that will serve your company for years to come. The ease of configuring EIGRP is also the main reason I see SO many misbehaving EIGRP networks in the field. A network engineer builds a small network for his com- pany. As time goes on the network gets larger and larger, and the routing environ- ment gets more and more complicated. EIGRP manages the routing on the network quite nicely, until one day things start to go wrong. The engineer who built the net- work can't figure out what's wrong, and consultants are called in who completely redesign the network. This is not to say that EIGRP is not a good routing protocol; I believe it is a very strong protocol. My point is that it's almost too easy to configure. You can throw two EIGRP routers on an Ethernet LAN with minimal configuration, and they will communicate and share routes. You can do the same with 10 or 20 or 100 routers, and they will all communicate and share routes. You can add 100 serial links with remote sites using EIGRP, and they will all communicate and shar