Routing Information Protocol Ver. 2
The immediate benefit of switching to RIPv2 is the ability to use VLSM. RIPv2 is considered a classless routing protocol, which means that when it sends routing updates it will include subnet information. This also allows the support of dis-contiguous networks. A dis-contiguous network is displayed in the following example.
You can see that the 192.168.1.0/26 network is connected to the 192.168.1.65/26 network through the 10.1.1.0/24 network. With RIPv1 this configuration would not be possible. This is because RIPv1 is classful, so router 2 would advertise the classful network 192.168.1.0/24 to router 3 and router 3 would also advertise 192.168.1.0/24 to router 2. Since RIPv2 sends subnet information this type of network is not an issue.
Multicast Updating
RIPv2 also has a different way of sending updates to neighbors. Instead of broadcasting update messages out to anyone listening, RIPv2 multicasts updates to the 224.0.0.9 multicast address. All routers that are configured with RIPv2 will listen for multicasts directed to the 224.0.0.9 multicast address.
Authentication
Another advantage of RIPv2 is the ability to authenticate routing updates. Authentication of routing updates is extremely important because RIP will typically believe any routing update it receives. This opens up security holes in the network, such as someone sending spoofed routing updates to reroute them in order to gain access to sensitive information. RIPv2 supports two types of authentication, plain text authentication, and md5 authentication.
Plain Text Authentication
Plain text authentication is definitely less secure. Authentication parameters are sent in plain text across the network opening up the possibility for someone to sniff the traffic and retrieve the information. I would always recommend going with md5 authentication.
MD5 Authentication
MD5 authentication encrypts authentication parameters and allows routers to securely authenticate routing updates. As you might have guessed MD5 authentication uses the MD5 encryption. The MD5 encryption generates a 128 bit message from the password to send for authentication.
Let's go ahead and configure our previous network with RIPv2 and authentication.
Let's go ahead and configure our previous network with RIPv2 and authentication.