Re: OSPF Virtual Links and PPPoFR

Hello Joe / Bryan / Brian,

Well... I've reacheability to all interfaces involved and my Virtual
Interfaces work well, even the advertisements go thru without problem....
but I can't have working the VL from the hub to the spoke (from spoke to
spoke it works OK). Once I change the ospf interface type on the three
routers to point-to-multipoint.... the whole scenario is working, that's why
I think it's something related to the interface type / PPP.
I checked the link you sent me and the scenario descripted is pretty pretty
much similar to mine and I see the guy also had many problems but I had the
layer 2 working correctly until the VL appears

I know your suggestions guys are the best practices of course, I just wanted
to try something weird. Whatever, thank very much for your advise. Let see
if someone else has any advise. I will keep investigating.

Thanks & Brgds..... Victor.

On Wed, Jul 15, 2009 at 10:28 PM, Bryan Bartik <bbartik_at_ipexpert.com> wrote:

> Can you ping R1's loopback from R2 and R3? It may be a reachability problem
> with PPPoFR in a hub and spoke topology. I have seen certain instances where
> the hub brings up multiple virtual-access interfaces but it sends packets
> down the wrong one.
>
> Example, the following output is from a Hub, R2. 10.1.1.1 is a loopback on
> R1:
>
> O IA 10.1.1.1 [110/2] via 172.16.0.1, 00:00:06, Virtual-Access3
>
> However the, the virtual-access3 interface is bound to the DLCI headed
> towards R3. The virtual-access interface is created dynamically.
>
> R2#sho ip osp ne
>
> Neighbor ID Pri State Dead Time Address Interface
> 10.1.1.3 0 FULL/ - 00:01:39 172.16.0.3
> Virtual-Access3
> 10.1.1.1 0 FULL/ - 00:01:39 172.16.0.1
> Virtual-Access2
>
> R2 cannot reach R1 and virtual-links will not come up because of this. I
> think the root of the problem is having two interfaces (virtual-acess
> interfaces in this case) with one IP address. You can try to remove pieces
> of your configuration and add them back, you can try multiple templates
> (with the same IP), or even try changing network types, but the chances of
> this happening seem to be pretty good.
>
> I found this blog entry, but I am not sure ip unnumbered will help in your
> case, may be worth a shot. I was not able to get it to work.
>
>
> http://cciepursuit.wordpress.com/2008/09/21/ios-error-with-ospf-point-to-multipoint-network-in-pppofr-hub-and-spoke-topology/
>
>
> On Wed, Jul 15, 2009 at 5:56 PM, Victor <cisco.all.stuff_at_gmail.com> wrote:
>
>> I have 3 routers 1,2 and 3... where 2 is the hub, all of them are ABRs
>> sharing the area 77 and have other area configured in theirs Loopback
>> interfaces. Router 1 has a Lo with Area 0, Router 2 has a Lo with Area 2
>> and
>> Router 3 has a Lo with Area 3. So I'm trying to connect the Areas 2 and 3
>> to
>> Area 0 through Area 77 ( area 77 virtual-link Router1-ID and viceversa)
>>
>> I hope now is clearer.
>>
>> Thanks and Brgds..... Victor
>>
>> On 7/15/09, Joe Astorino <jastorino_at_ipexpert.com> wrote:
>> >
>> > What do your areas look like?
>> >
>> > - what is the area between hub and spoke 1
>>
>>
>> - what is the area between hub and spoke 2
>>
>> - Do you have any other areas configured for something like loopbacks?
>>
>>
>> On Wed, Jul 15, 2009 at 6:09 PM, Victor <cisco.all.stuff_at_gmail.com>
>> wrote:
>> >
>> >> Understand.... the initial config is with the default interface type
>> >> (point-to-point for PPPoFR) in this case I can't have the VL up between
>> the
>> >> hub and one spoke (spoke has the area 0) but I can have up the VL
>> between
>> >> both spokes. After changing the config (interfaces ospf type point to
>> >> multipoint) both VL come up. My question is: if the interfaces type in
>> the
>> >> first case are equal / compatible, why the VL does not come up between
>> >> hub-spoke?? I think it may be simple but I'm missing it.
>> >>
>> >> Thanks & Brgds..... Victor.
>> >>
>> >> On 7/15/09, Joe Astorino <jastorino_at_ipexpert.com> wrote:
>> >>>
>> >>> I'm confused about your question now -- Can you please re-word that?
>> >>> What was the "original configuration" and what is the configuration
>> now? In
>> >>> general, the OSPF network types should match. You can get away with
>> >>> mismatches in some cases by tweaking timers, but I wouldn't recommend
>> it
>> >>> unless you need to for a task.
>> >>>
>> >>> On Wed, Jul 15, 2009 at 4:48 PM, Victor <cisco.all.stuff_at_gmail.com
>> >wrote:
>> >>>
>> >>>> Sorry...... a clarification when I said: "by default the ospf network
>> >>>> type for FR multipoint subinterfaces is multipoint non_broadcast"....
>> I
>> >>>> really meant non_broadcast..... by mistake I repeated multipoint.
>> >>>>
>> >>>> Brgds.......Victor.
>> >>>>
>> >>>>
>> >>>> On 7/15/09, Victor <cisco.all.stuff_at_gmail.com> wrote:
>> >>>>>
>> >>>>> Thank you very much Brian and Joe,
>> >>>>>
>> >>>>> That was the point...... now I have this working, I changed the
>> network
>> >>>>> type to point-to-multipoint, however I couldn't understand well
>> what's
>> >>>>> happening. Well....by default the ospf network type for FR
>> multipoint
>> >>>>> subinterfaces is multipoint non_broadcast and the ospf network type
>> when
>> >>>>> using PPPoFR is poin-to-point (Virtual Access) but all the
>> interfaces have
>> >>>>> the same network type, should not they work??
>> >>>>>
>> >>>>> So, with the initial config they became neighbors but the Virtual
>> Link
>> >>>>> do not comes up, after I changed to p-t-m it's working
>> >>>>>
>> >>>>> Sorry if I'm asking and stupidity but I've been searching on the
>> Cisco
>> >>>>> docs and I didn't find much information about these details.
>> >>>>>
>> >>>>> Could you pls add some other information on this issue?? Thanks
>> again
>> >>>>> for your help
>> >>>>>
>> >>>>>
>> >>>>> Cheers.... Victor.
>> >>>>>
>> >>>>> On 7/15/09, Brian Dennis <bdennis_at_internetworkexpert.com> wrote:
>> >>>>>>
>> >>>>>> Victor,
>> >>>>>> Did you check to see what the OSPF network type is on the hub's
>> >>>>>> interface when using standard FR and then when using PPPoFR?
>> >>>>>>
>> >>>>>> Brian Dennis, CCIEx5 #2210 (R&S/ISP-Dial/Security/SP/Voice)
>> >>>>>> bdennis_at_internetworkexpert.com
>> >>>>>>
>> >>>>>> Internetwork Expert, Inc.
>> >>>>>> http://www.InternetworkExpert.com<
>> http://www.internetworkexpert.com/>
>>
>> >>>>>> Toll Free: 877-224-8987 x 703
>> >>>>>> Outside US: 775-826-4344 x 703
>> >>>>>>
>> >>>>>> ----- Original Message -----
>> >>>>>> From: "Victor" <cisco.all.stuff_at_gmail.com>
>> >>>>>> Sent: Tue, July 14, 2009 19:39
>> >>>>>> Subject:OSPF Virtual Links and PPPoFR
>> >>>>>>
>> >>>>>>
>> >>>>>> Hello Guys,
>> >>>>>> I've been trying to get running OSPF Virtual Links over a 3 routers
>> >>>>>> topology
>> >>>>>> 1 hub + 2 spokes using PPPoFR for connecting between them, where
>> one
>> >>>>>> of the
>> >>>>>> spokes is the backbone and I have some Loopbacks created on each
>> >>>>>> router on
>> >>>>>> different areas, so finally I only can get running the Virtual Link
>> >>>>>> going
>> >>>>>> from spoke to spoke but NEVER the VL between the hub to the spoke
>> >>>>>> (area 0).
>> >>>>>> I changed the PPPoFR config and used only FR and everything works
>> OK,
>> >>>>>> when I
>> >>>>>> try to use PPPoFR (no changes in OSPF config) I get the same
>> problem.
>> >>>>>>
>> >>>>>> I'm sure I'm missing something..... do you have any suggestion??
>> >>>>>>
>> >>>>>> Regards.... Victor.
>> >>>>>>
>> >>>>>>
>> >>>>>> Blogs and organic groups at http://www.ccie.net
>> >>>>>>
>> >>>>>>
>> >>>>>>
>> _______________________________________________________________________
>> >>>>>> Subscription information may be found at:
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>> >>>>>>
>> >>>>>>
>> >>>>>>
>> >>>>>>
>> >>>>>>
>> >>>>>>
>> >>>>>>
>> >>>>>>
>> >>>>>>
>> >>>>>> ----- End of original message -----
>> >>>>>>
>> >>>>>>
>> >>>>>
>> >>>>
>> >>>>
>> >>>
>> >>>
>> >>>
>> >>> --
>> >>> Regards,
>> >>>
>> >>> Joe Astorino - CCIE #24347 R&S
>> >>> Technical Instructor - IPexpert, Inc.
>> >>> Cell: +1.586.212.6107
>> >>> Fax: +1.810.454.0130
>> >>> Mailto: jastorino_at_ipexpert.com
>> >>>
>> >>
>> >>
>> >>
>> >
>> >
>> >
>> > --
>> > Regards,
>> >
>> > Joe Astorino - CCIE #24347 R&S
>> > Technical Instructor - IPexpert, Inc.
>> > Cell: +1.586.212.6107
>> > Fax: +1.810.454.0130
>> > Mailto: jastorino_at_ipexpert.com
>>
>>
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>
>
> --
> Bryan Bartik
> CCIE #23707 (R&S), CCNP
> Sr. Support Engineer - IPexpert, Inc.
> URL: http://www.IPexpert.com

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Received on Wed Jul 15 2009 - 23:37:16 ART