[j-nsp] ng-mvpn problem

Antonio Sanchez-Monge amonge at juniper.net
Tue Oct 22 18:49:14 EDT 2013


You need PIM in the interface towards the source IMHO



On 10/23/13 12:47 AM, "Stacy W. Smith" <stacy at acm.org> wrote:

>Yes, that would also work, but since logical-system a is really just
>emulating a multicast source, there's really no need for it to run PIM. A
>typical multicast source would not be running PIM.
>
>--Stacy
>
>On Oct 22, 2013, at 4:44 PM, Antonio Sanchez-Monge <amonge at juniper.net>
>wrote:
>> Solution would be setting a higher PIM priority in lt-1/1/10.770, so
>>that
>> it becomes the DR
>> 
>> 
>> 
>> 
>> On 10/23/13 12:40 AM, "Antonio Sanchez-Monge" <amonge at juniper.net>
>>wrote:
>> 
>>> That's a brilliant analysis Stacy, I think you nailed it (awaiting
>>>Mihai's
>>> confirmation).
>>> 
>>> 
>>> On 10/22/13 11:59 PM, "Stacy W. Smith" <stacy at acm.org> wrote:
>>> 
>>>> On Oct 22, 2013, at 2:44 PM, Mihai <mihaigabriel at gmail.com> wrote:
>>>>> Removing PIM fromlt-1/1/10.770 is not a solution because the PE will
>>>>> not learn about the source and the multicast group.
>>>> 
>>>> Actually, removing lt-1/1/10.770 from PIM would allow the source and
>>>> multicast group to be learned, and fix the problem (as long as
>>>>multicast
>>>> routing was still enabled on the lt-1/1/10.770 interface).
>>>> 
>>>> The problem is that there's a PIM neighbor relationship between a and
>>>>x.
>>>> Because of your IP addressing, a is the DR for the a-x LAN.
>>>> 
>>>> Because you are injecting traffic with ping and "bypass-routing
>>>>interface
>>>> lt-1/1/10.771" logical-system a is NOT the first-hop router. It's
>>>>simply
>>>> acting as a multicast source that's pumping traffic with destination
>>>>IP
>>>> 225.10.10.10 out the lt-1/1/10.771 interface.
>>>> 
>>>> Logical-system x instance mvpn receives this traffic on lt-1/1/10.770
>>>>and
>>>> does not forward it because it is not the DR.
>>>> 
>>>> Therefore, the logical-system x instance mvpn doesn't learn about the
>>>> active (S,G).
>>>> 
>>>> Another way to solve this problem is disabling PIM on logical-system
>>>>a.
>>>> This will make lt-1/1/10.770 on logical-system x instance mvpn the DR,
>>>> and cause it to learn about the active S,G (and therefore generate the
>>>> NG-MVPN Type 5 route).
>>>> 
>>>> I have mocked up your configuration in the lab and confirmed that
>>>> removing PIM from logical-system a fixes the issue.
>>>> 
>>>> --Stacy
>>>> 
>>>> 
>>>> 
>>> 
>> 
>> 
>
>
>





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