SPECIAL RULES: For Transmitting and Receiving RIP packets, the following rules apply.
If the router is not configured to authenticate RIP-2 messages then RIP-1 and any unauthenticated RIP-2 messages are accepted, authenticated RIP-2 messages are discarded.
If the router is configured to authenticate RIP-2 messages then RIP-1 messages and RIP-2 messages that pass authentication testing are accepted, unauthenticated and failed authentication RIP-2 messages are discarded.
There are 2 ways that a router can broadcast RIP-2 messages. One way is to use the broadcast address in RIP-1 or it can use a well-known multi cast address 224.0.0.9 to send the RIP packet.