User Manual

M4300 Intelligent Edge Series Fully Managed Stackable Switches
Configure OSPF and OSPFv3 User Manual379
State The state of a neighbor can be the following:
• Down.
This is the initial state of a neighbor conversation. It indicates that no
recent information was received from the neighbor. On NBMA networks,
hello packets can still be sent to Down neighbors, although at a reduced
frequency.
• Attempt.
This state is valid only for neighbors attached to NBMA networks.
It indicates that no recent information was received from the neighbor, but
that a more concerted effort must be made to contact the neighbor. This is
done by sending the neighbor hello packets at hello intervals.
• Init.
A hello packet was recently seen from the neighbor. However,
bidirectional communication was not yet established with the neighbor (for
example, the router 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. Communication between the two routers is bidirectional.
This was
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.
State
(continued)
• Exchange. The
router is describing its entire link state database by sending
database description packets to the neighbor. The link state request
packets can also be sent asking for the neighbor's more recent LSAs. All
adjacencies in the 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. Link state request packets are sent to the neighbor asking for the
more recent LSAs that were discovered (but not yet received) in the
exchange state.
• Full. The
neighboring routers are fully adjacent. These adjacencies now
appear in router LSAs and network LSAs.
Events The number of times this neighbor relationship changed state, or an error
occurred.
Permanence This variable displays the status of the entry. Dynamic and Permanent refer to
how the neighbor became known.
Hellos Suppressed This indicates whether hellos are being suppressed to the neighbor.
Retransmission Queue
Length
An integer representing the current length of the retransmission queue of the
specified neighbor router ID of the specified interface.
Up Time Neighbor uptime; how long since the adjacency last reached the Full state.
Dead Time The amount of time, in seconds, to wait before the router assumes the neighbor
is unreachable.
Table 135. OSPF Neighbor Table (continued)
Field Description