Configuring the OSPF Routing Protocol (Layer 3)

2.Use Table 9-8 to review the OSPF neighbors parameters:

Table 9-8.OSPF Neighbors Parameters

Parameter

Definition

 

 

IP Address

The IP address associated with the OSPF neighbor.

 

 

State

The functional level of an interface. States include:

 

•

Down - This is the initial state of a neighbor conversation. It

 

 

indicates that there has been no recent information received

 

 

from the neighbor.

 

•

Attempt - Indicates that no recent information has been

 

 

received from the neighbor, but that a more concerted effort

 

 

should be made to contact the neighbor

 

•

INIT - Indicates that the Hello packet has recently been seen

 

 

from the neighbor. However, bidirectional communication

 

 

has not yet been established with the neighbor.

 

•

2-Way- Communication between the two routers is

 

 

bidirectional.

 

•

ExStart - 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 - Router is describing its entire link state database

 

 

by sending Database Description packets to the neighbor.

 

•

Loading - 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 - The neighboring routers are fully adjacent. These

 

 

adjacencies will now appear in router-LSAs and

 

 

network-LSAs.

 

 

Router ID

The router ID of the neighbor.

 

 

Master

The state of the neighbor: master or slave.

 

 

DD Number

The hexadecimal number used to sequence the collection of

 

Database Description Packets. The initial value (indicated by the

 

Init bit being set) should be unique. The DD sequence number

 

then increments until the complete database description has

 

been sent.

 

 

DR Priority

Displays the DR Priority of the neighboring router.

 

This is used to determine whether this neighbor is eligible to

 

become the Backup Designated Router. If 0, the router is

 

ineligible to become the Backup Designated Router.

 

 

E-Option

The method used to flood AS-external-LSAs.

 

 

T-Option

Specifies whether this neighbor is an ASBR.

 

 

MC-Option

Specifies whether this neighbor supports MOSPF.

 

 

 

Cajun P550/P220 Switch Operation Guide

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