Re: ospf network type non-broadcast

From: Paul Cosgrove (paul.cosgrove@heanet.ie)
Date: Fri May 16 2008 - 09:36:59 ART

Hi Chuck,

Could you try the following:
a) shutdown the serial interfaces
b) clear each ospf process
c) no shut

and then see if the ospf neighbors re-establish. I'm wondering if this
is due to a previous config causing the same neighbors to be known
before you made some of these changes.

Paul.

Chuck Ryan (chryan) wrote:
> Here are my configurations, nothing fancy, all pretty basic.
>
> ****** R1 *******
>
> interface serial1/0
> ip address 10.0.0.1 255.0.0.0
> encapsulation frame-relay
> no fair-queue
> serial restart-delay 0
> no arp frame-relay
> frame-relay map ip 10.0.0.3 103
> frame-relay map ip 10.0.0.2 102
> no frame-relay inverse-arp
>
>
> router ospf 1
> network 0.0.0.0 255.255.255.255 area 0
>
>
> ****** R2 *******
>
> interface serial1/0
> ip address 10.0.0.2 255.0.0.0
> encapsulation frame-relay
> no fair-queue
> serial restart-delay 0
> no arp frame-relay
> frame-relay map ip 10.0.0.3 201
> frame-relay map ip 10.0.0.1 201
> no frame-relay inverse-arp
>
>
> router ospf 1
> network 0.0.0.0 255.255.255.255 area 0
>
>
> ****** R3 *******
>
> interface serial1/0
> ip address 10.0.0.3 255.0.0.0
> encapsulation frame-relay
> no fair-queue
> serial restart-delay 0
> no arp frame-relay
> frame-relay map ip 10.0.0.1 301
> frame-relay map ip 10.0.0.2 301
> no frame-relay inverse-arp
>
>
> router ospf 1
> network 0.0.0.0 255.255.255.255 area 0
>
> Thanks,
>
> Chuck
>
> ________________________________
>
> From: Michel Grossenbacher [mailto:pashtuk@gmail.com]
> Sent: Friday, May 16, 2008 6:41 AM
> To: Chuck Ryan (chryan)
> Cc: Hong Chan; Cisco certification
> Subject: Re: ospf network type non-broadcast
>
>
> Hi Chuck
> Can you provide your FR and OSPF configs for all three Routers?
> best regards
>
> Michel
>
>
> On 16/05/2008, Chuck Ryan (chryan) <chryan@cisco.com> wrote:
>
> Hi Hong,
>
> I dont have any problem establishing adjacencies with or without
> the
> neighbor statements configured under the ospf routing process.
> That is
> what I don't understand. I thought with a network type of
> non-broadcast,
> you have to manually define your neighbors on your DR in order
> to
> establish adjacencies. As it turns out for me, that's not the
> case. I
> can establish ospf adjacencies with the neighbor statements AND
> without
> the neighbor statements.
>
> I'm trying to find out why this works with no neighbor
> statements
> configured, and no broadcast statement at the end of my
> frame-relay map
> statements.
>
> Thanks,
>
> Chuck
>
> ________________________________
>
> From: Hong Chan [mailto:howard.chan34@gmail.com]
> Sent: Friday, May 16, 2008 12:50 AM
> To: Chuck Ryan (chryan)
> Subject: Re: ospf network type non-broadcast
>
>
> Where is your DR? Is that on the r1?
> Try to add "ip ospf priority 0" on r2 & r3, add neighbor
> statement on
> r1. If still not able to form neighborship, try debug to see
> how's the
> hello packet talking.
>
>
> 2008/5/16 Chuck Ryan (chryan) <chryan@cisco.com>:
>
>
> Hi GS,
>
> I have a question about the ospf network type,
> non-broadcast. In
> a
> simple 3 router pod, with r1 being the hub and r2 and r3
> being
> the
> spokes, I've been reading how you need to configure a
> neighbor
> statement
> under r1 in order to establish ospf adjacencies with r2
> and r3.
>
> When I lab it up and try it, it does work. What I have
> also
> found out,
> is that no neighbor statement is necessary in order to
> get ospf
> adjacencies up between r1 and r2, and r1 and r3. Frankly,
> I
> don't see
> the difference whether I manually define neighbors or
> not, the
> results
> appear to be the same.
>
> Can someone explain this behavior? I thought that if you
> do not
> specify
> the neighbor statement, then the adjacencies will not
> come up,
> but that
> doesn't appear to be the case. Also, I am not using the
> "broadcast"
> keyword on my frame-relay map statements.
>
> Thanks,
>
> Chuck
>
>
>
>
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