Re: OSPF neighbour and adjacency

Salam,

Adjacencies

The fact that routers are neighbors is not sufficient to guarantee an
exchange of link-state updates; they must form adjacencies to exchange
link-state updates. Adjacency is an advanced form of neighborship formed by
routers that are willing to exchange routing information after negotiating
parameters of such an exchange. Routers reach a FULL state of adjacency when
they have synchronized views on a link-state database.

Interface type plays a major role in how the adjacencies are formed. For
example, neighbors on point-to-point links always try to become adjacent,
while routers attached to broadcast media such as Ethernet can choose to
become adjacent only with a subset of neighboring routers on the interface.

Once a router decides to form an adjacency with a neighbor, it starts by
exchanging a full copy of its link-state database. The neighbor, in turn,
exchanges a full copy of its link-state database with the router. After
passing through several neighbor states, the routers become fully adjacent.
Neighbor States

You can use the *show ip ospf neighbor* command to determine the state of
the OSPF neighbor or neighbors. The output of this command will most likely
reveal one of these:

   -

   nothing at all
   -

   state = down
   -

   state = init
   -

   state = exstart
   -

   state = exchange
   -

   state = 2-way
   -

   state = loading

There are other OSPF states, but those shown here are the most common ones
seen in *show ip ospf neighbor* command output. For an explanation of all
the OSPF neighbor states, refer to OSPF Neighbor
States<http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a0080093f0e.shtml>
.

if unable to understand then try to read these article ...

http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a0080094050.shtml
http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a0080093f0e.shtml

Regards,
M. Faisal

On Sat, Jan 30, 2010 at 10:55 AM, HEMANTH RAJ <hemanthrj_at_gmail.com> wrote:

> Can anyone tell me the difference between ospf neighbor and adjacency?
> Generally wat is the difference between neighbour and adjacency in any
> routing protocol?
>
> --
> Problems arise Bcoz we talk,prblms r not solve bcoz we dont talk So gud r
> bad talk to ur affectionate one's freely
>
> Urs Friendly,
> HP HEMANTH RAJ
>
>
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Received on Sat Jan 30 2010 - 13:16:58 ART