From: Chris Lewis (chrlewiscsco@gmail.com)
Date: Wed Feb 01 2006 - 13:53:55 GMT-3
Agreed,
If the hub is the DR, either you hve neighbor statements on each spoke OR
two neighbor statements on the hub will suffice. IMHO linking a neighbor
configuration with ip ospf priority configuration is misleading, as they are
two different things.
Chris
On 2/1/06, Gustavo Novais <gustavo.novais@novabase.pt> wrote:
>
> Hi,
> In fact this is a bit of mislead between theory and practice.
> If you try it out, you'll see that just configuring neighbors on hub
> will work.
> Regarding the ip priority 0, as I was remembered by GS some time ago, it
> is not a requisite for this type of topology. Things will work if you
> don't set it to 0. But probably they will not work the way you wish to.
>
> Regarding of how will the spokes know where is the HUB (DR), if you
> remember you configured neighbor x.x.x.x (which by default configures
> this remote neighbor with priority 0) on the hub.
>
> So, what will happen is that each hub will send unicast hellos and DBD's
> (because of neighbor command) coming from a router (HUB). There is your
> answer. They will engage in DR/BDR election, on the moment that spoke
> receives that DBD, and reply to its source. If you configured spoke
> with lower priority than hub, spoke will become BDR (or non-dr).
>
> Hence in practice you do not need to configure neighbor on spoke
> routers.
>
> My 0.02$
>
> Gustavo Novais
>
> -----Original Message-----
> From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
> Popgeorgiev Nikolay
> Sent: quarta-feira, 1 de Fevereiro de 2006 15:50
> To: ccielab@groupstudy.com
> Subject: ospf misunderstanding
>
> Dear all,
>
> I have a small question about ospf, network types and frame-relay.
>
> Here is a sample network:
>
> two spokes, one hub. The requirement is to enable ospf between them and
> to use non-broadcast network type on the interfaces.
>
> This leads to a DR/BDR election, and according to me the DR should be on
> the hub and there shouldn't be BDR.
> Also I have to put "ip ospf priority 0" on my spoke routers' interfaces
> right?
> Cause the network doesn't allow multicasts I have to specify neighbors -
> two from the DR and one on each spoke.
> BUT in a solution from a work book I saw this sentence :
>
> "The neighbor statements are required only on interfaces that are NOT
> configured with ip ospf priority 0 (which means spokes don't need
> neighbor command)"
>
> SO how does the spokes find where to make their adjacency ?
>
>
> thanks,
> Nick
>
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