EIGRP Notes – Message Types
Please correct if I’m being stupid…which is a lot of the time.
Hello : Discovers and maintains neighbors
Destination: 224.0.0.10 Important fields: K values
Update : An update to the topology such as a route withdrawal or a metric change
Destination: 224.0.0.10 -or- unicast during neighbor discovery Important fields: Message sequence number Route being updated including k values to compute metric
Query : Used to ask a neighbor if it has a route to a certain network; see stuck-in-active
Destination: 224.0.0.10 Important fields: Message sequence number Network being queried
Reply : Sent in response to a query message telling a router whether or not it has a route
Destination: Important fields: Message sequence number Sequence number of message to ack Network being queried along with k values to compute metric
Ack : Used to acknowledge updates, queries, replies
Destination: Unicast address of router Important fields: Sequence number of message to ack
I know it’s rarely mentioned but isn’t there a goodbye message too?
steven iveson
12 Dec 11 at 18:57
There is a goodbye message, Steven, but it’s a fairly new feature introduced around 12.3(2). A long time ago, but still not testable, I guess, since it’s not mentioned in any of my reading. It looks to be only used when you shut down the EIGRP process gracefully.
Aaron Conaway
14 Dec 11 at 17:42