User Manual

Routing
282
M6100 Web Management User Guide
State The state of a neighbor can be the following:
• Down — This is the initial state of a neighbor
conversation. It indicates that there has been no
recent information received from the neighbor.
On NBMA networks, Hello packets may still be
sent to Down neighbors, although at a reduced
frequency.
• Attempt — This state is only valid for neighbors
attached to NBMA networks. It indicates that no
recent information has been received from the
neighbor, but that a more concerted effort should
be made to contact the neighbor. This is done by
sending the neighbor Hello packets at intervals
of Hello Interval.
• Init — In this state, a Hello packet has recently
been seen from the neighbor. However,
bidirectional communication has not yet been
established with the neighbor (i.e., the router
itself did not appear in the neighbor's Hello
packet). All neighbors in this state (or greater)
are listed in the Hello packets sent from the
associated interface.
• 2-Way — In this state, communication between
the two routers is bidirectional. This has been
assured by the operation of the Hello Protocol.
This is the most advanced state short of
beginning adjacency establishment. The
(Backup) Designated Router is selected from the
set of neighbors in state 2-Way or greater.
• Exchange Start — This is the first step in
creating an adjacency between the two
neighboring routers. The goal of this step is to
decide which router is the master, and to decide
upon the initial DD sequence number. Neighbor
conversations in this state or greater are called
adjacencies.
• Exchange — In this state the router is describing
its entire link state database by sending
Database Description packets to the neighbor. In
this state, Link State Request Packets may also
be sent asking for the neighbor's more recent
LSAs. All adjacencies in Exchange state or
greater are used by the flooding procedure.
These adjacencies are fully capable of
transmitting and receiving all types of OSPF
routing protocol packets.
• Loading — In this state, Link State Request
packets are sent to the neighbor asking for the
more recent LSAs that have been discovered
(but not yet received) in the Exchange state.
• Full — In this state, the neighboring routers are
fully adjacent. These adjacencies will now
appear in router-LSAs and network-LSAs.
Field Description