Re: OSPF Weird Issue

Hello,

There is a synchronization problem. If a router receive a unicast hello from
another router he
will automatically respond back with unicast hello. When you delete the
neighbor command,
you will bring down the state of neighbor adjacency on the router you issued
the command.
On the other end the ospf neighbor state will still be FULL and will sent
unicast OSPF packets
causing the overall adjacency to come back to FULL state.

You still need to consider the DR/BDR election process, because there is a
multi-access network type.
The best way is to configure the neighbor command only on DR and BDR as well
as setting
the opsf priority to zero on the others.

So, in order to achieve what you want you need to remove the neighbor
command on the DR/BDR
(or in all routers if you configured them all) and reset the ospf process at
the same time.

HTH,

On Mon, Jun 13, 2011 at 12:56 PM, Routing Freak <routingfreak_at_gmail.com>wrote:

> Hey Roy
> Here it is not Hub n spoke network.Just 4 routers are in Non broadcast
> domain and each has frame relay mapping statement to each other .So there
> is
> no problem of reachability .And also there is no invere arp problem ,
> because i disabled the inverse arp also.Still the problem presists
>
> I dont have the configs file
> I just didnt save my configs
> Just try to do a NBMA network in OSPF
>
>
> On Mon, Jun 13, 2011 at 2:50 PM, Roy Khan <roykhan123_at_hotmail.com> wrote:
>
> >
> > Hi
> >
> > NBMA mode send hello as unicast and it need the neighbor statement and
> also
> > perform DR/BDR election.
> > also it require layer 3 to layer 2 resolution in FR.
> > Configure the DR which have full connectivity to the others routers in
> your
> > case it should me hub. the spoke cannt be
> > DR becuase it does not have full layer 2 connectivity with each other.
> manually
> > set the OSPF pri to zero.
> > Disable inverse arp in FR. and also HUB have to FR statement point to the
> > spoke and spoke point to hub
> > first configure the FR and check and test and then configure the OSPF.
> >
> > > Date: Mon, 13 Jun 2011 11:28:29 +0530
> > > Subject: OSPF Weird Issue
> > > From: routingfreak_at_gmail.com
> > > To: ccielab_at_groupstudy.com
> >
> > >
> > > Hi all
> > > I got this log message when i m doing OSPF labs
> > >
> > > Consider a fully-meshed frame-relay network with three routers. The
> three
> > > routers are connected to the the frame relay cloud with the IP
> addresses
> > > 10.10.10.1, 10.10.10.2 and 10.10.10.3 respectively. However, the
> neighbor
> > > relationship on all the routers constantly keeps getting reset with
> > messages
> > > like the following -
> > >
> > >
> > > *Mar 4 16:10:01.333: %OSPF-5-ADJCHG: Process 100, Nbr 10.10.10.3 on
> > > Serial2 from LOADING to FULL, Loading Done
> > > *Mar 4 16:10:05.261: %OSPF-5-ADJCHG: Process 100, Nbr 10.10.10.3 on
> > > Serial2 from FULL to DOWN, Neighbor Down: Adjacency forced to reset
> > > *Mar 4 16:10:05.521: %OSPF-4-NONEIGHBOR: Received database
> > > description from unknown neighbor 10.10.10.3
> > > *Mar 4 16:10:08.813: %OSPF-5-ADJCHG: Process 100, Nbr 10.10.10.2 on
> > > Serial2 from EXSTART to DOWN, Neighbor Down: Adjacency forced to reset
> > > *Mar 4 16:10:11.485: %OSPF-4-NONEIGHBOR: Received database
> > > description from unknown neighbor 10.10.10.2
> > > *Mar 4 16:10:12.593: %OSPF-5-ADJCHG: Process 100, Nbr 10.10.10.3 on
> > > Serial2 from LOADING to FULL, Loading Done
> > > *Mar 4 16:10:14.905: %OSPF-5-ADJCHG: Process 100, Nbr 10.10.10.3 on
> > > Serial2 from FULL to DOWN, Neighbor Down: Adjacency forced to reset
> > > *Mar 4 16:10:19.013: %OSPF-5-ADJCHG: Process 100, Nbr 10.10.10.2 on
> > > Serial2 from EXCHANGE to DOWN, Neighbor Down: Adjacency forced to
> > > reset
> > >
> > >
> > > Given just this information, can you determine what the problem might
> be
> > > here?
> > >
> > > What is meant by OSPF NonNeighbor and unknown neighbor?
> > >
> > >
> > > Blogs and organic groups at http://www.ccie.net
> > >
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-- 
Rares Donca
CCIE #28430 (R&S)
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