RIPng (Routing Information Protocol next generation)

You would have learnt about RIP and RIPv2. RIPng does the same thing as RIP and RIPv2. Well, almost the same thing. With few differences of course. Some of the important points are given below.

• Similar to RIP and RIPv2, RIPng is also a distance vector routing protocol which uses hop counts as a metric to determine the best path to reach  to a destination. 
• Similar to RIP and RIPv2, RIPng also has a maximum hop count of 15. One thing you need to notice here is RIP and RIPv2 uses IPv4 addressing and RIPng makes use of IPv6 addressing. Hence you would normally see that the hop count to reach a destination network will always be 1 more than what you can see in RIP and RIPv2. That's how IPv6 addressing works folks.
• RIPng also makes use of split horizon, poison reverse and similar techniques to avoid loops in a network
• RIP and RIPv2 uses UDP with port number 520 where as RIPng uses UDP port number 521
• RIPv2 uses the multicast address 229.0.0.9 for sending and receiving routing updates. RIPng uses the IPv6 multicast address FF02::9 for the same.
• RIPng does not support authentication on its own. The IPSec feature of IPv6 can be used to provide authentication for out RIPng packets. More on authentication of RIPng in another article. 
• RIPng is supported on Cisco IOS 12.2(2)T and above.