RIPng packets
RIPng uses request and response packets to exchange routing information as follows:
When RIPng starts or needs to update some route entries, it sends a multicast request packet to neighbors.
When a RIPng neighbor receives the request packet, it sends back a response packet that contains the local routing table. RIPng can also advertise route updates in response packets periodically or advertise a triggered update caused by a route change.
After RIPng receives the response, it checks the validity of the response before adding routes to its routing table, such as whether the source IPv6 address is the link-local address and whether the port number is correct. A response packet that fails the check is discarded.