OSPF HELLO Packets Information
OSPF’s HELLO packet, in its neighbor set up process plays an important role, we need to know about its structure and content package.
1, ROUTER-ID of the originating router (in addition to this, the other for the interface parameters)
2, Area ID
3, ADDRESS MASK
4, Authentication Type and Authentication information
5, HELLO INTERVAL
6, ROUTER DEAD INTERVAL
7, ROUTER PRIORITY
8, DR and BDR
9, FIVE FLAG BITS signifying optional capabilities
10, ROUTER ID of the originating router’s neighbors.This list contains only routers from which hellos were heard on the originating interface withii the last Router Dead Interval.
Note: ROUTERID neighbors contained herein are found on the interface rather than the other interface on the router. OSPF interface on the other neighbors did not need to come through the HELLO packet on this interface you know the neighbors, they are by the LSA to collect the entire OSPF topology.