Gian,

I just labbed this up myself again to verify everything and I am not having
the intermittent issues.  However, in my lab testing I did run into
something that will cause this problem, so I want you to double check your
configuration.  If you happen to forget "ip pim nbma-mode" on R6 the
frame-relay hub you will have bad things happen -- essentially the tunnel
interfaces on the PEs will go up/up but they will never form a PIM
adjacency. With you PIM over the tunnel, you are SOL so make sure you have
that!



On Sun, Mar 7, 2010 at 6:39 PM, Steve Shaw <[email protected]> wrote:

> Check for RPF failures between the source and the destination. The first
> ping has succeeded for me in the past due to traffic flowing down the shared
> tree but once the DR switches over to the SPT, and the second ping fails, I
> usually start looking for RPF failures.
>
>
> On Sun, Mar 7, 2010 at 6:33 PM, Joe Astorino <[email protected]>wrote:
>
>> Oh -- The other thing I would have liked to see in that situation is if R1
>> and R7 both still know who the RP is at that point when it is failing.  Do
>> further pings also fail or does it come back up?
>>
>>
>> On Sun, Mar 7, 2010 at 6:29 PM, Joe Astorino <[email protected]>wrote:
>>
>>> That does seem strange.  You should not have inconsistent results like
>>> that.  At that point, I would be looking to see what is going on in your SP
>>> core there.
>>>
>>> Things look to be OK on R1, but all the magic is happening starting with
>>> R2.  I would keep my eye on R2 and see if you have anything flapping (MP-BGP
>>> session to R4, PIM adjacency over your tunnel0 interface), etc...
>>>
>>> If things seem to be OK, I would start looking at debug ip mpacket and
>>> trying to isolate where the problem is coming from.
>>>
>>>
>>>
>>> On Sun, Mar 7, 2010 at 7:01 AM, Gian Paolo <[email protected]> wrote:
>>>
>>>> Hi all,
>>>> I'm watching VoD about Multicast VPN configurations while replicating
>>>> all the configs on dynamips.
>>>>
>>>> Everything's fine until a couple of minutes from the end of the video:
>>>> when I try to ping 239.7.7.7 from R1 as in the video I get an answer from
>>>> the first ping and then nothing:
>>>>
>>>>
>>>> *R1#sh ip mroute*
>>>> *
>>>> *
>>>> (*, 224.0.1.39), 01:21:28/stopped, RP 0.0.0.0, flags: DC
>>>> *  Incoming interface: Null, RPF nbr 0.0.0.0*
>>>> *  Outgoing interface list:*
>>>> *    FastEthernet0/0, Forward/Sparse-Dense, 01:21:28/00:00:00*
>>>> *
>>>> *
>>>> *(22.22.22.22, 224.0.1.39), 00:00:07/00:02:52, flags: PT*
>>>> *  Incoming interface: FastEthernet0/0, RPF nbr 10.0.12.2*
>>>> *  Outgoing interface list: Null*
>>>> *
>>>> *
>>>> *(*, 224.0.1.40), 01:26:14/stopped, RP 0.0.0.0, flags: DCL*
>>>> *  Incoming interface: Null, RPF nbr 0.0.0.0*
>>>> *  Outgoing interface list:*
>>>> *    FastEthernet0/0, Forward/Sparse-Dense, 01:26:14/00:00:00*
>>>> *
>>>> *
>>>> *(22.22.22.22, 224.0.1.40), 01:16:30/00:02:54, flags: PLT*
>>>> *  Incoming interface: FastEthernet0/0, RPF nbr 10.0.12.2*
>>>> *  Outgoing interface list: Null*
>>>> *
>>>> *
>>>> *R1#ping 239.7.7.7*
>>>> *
>>>> *
>>>> *Type escape sequence to abort.*
>>>> *Sending 1, 100-byte ICMP Echos to 239.7.7.7, timeout is 2 seconds:*
>>>> *
>>>> *
>>>> *Reply to request 0 from 10.0.47.7, 20 ms*
>>>> *
>>>> *
>>>> *R1#ping 239.7.7.7*
>>>> *
>>>> *
>>>> *Type escape sequence to abort.*
>>>> *Sending 1, 100-byte ICMP Echos to 239.7.7.7, timeout is 2 seconds:*
>>>> *.*
>>>> *R1#sh ip mroute*
>>>> *
>>>> *
>>>> *(*, 239.7.7.7), 00:00:10/stopped, RP 22.22.22.22, flags: SP*
>>>> *  Incoming interface: FastEthernet0/0, RPF nbr 10.0.12.2*
>>>> *  Outgoing interface list: Null*
>>>> *
>>>> *
>>>> *(1.1.1.1, 239.7.7.7), 00:00:10/00:03:25, flags: T*
>>>> *  Incoming interface: Null, RPF nbr 0.0.0.0*
>>>> *  Outgoing interface list:*
>>>> *    FastEthernet0/0, Forward/Sparse-Dense, 00:00:10/00:03:19*
>>>> *
>>>> *
>>>> *(*, 224.0.1.39), 01:21:43/stopped, RP 0.0.0.0, flags: DC*
>>>> *  Incoming interface: Null, RPF nbr 0.0.0.0*
>>>> *  Outgoing interface list:*
>>>> *    FastEthernet0/0, Forward/Sparse-Dense, 01:21:43/00:00:00*
>>>> *
>>>> *
>>>> *(22.22.22.22, 224.0.1.39), 00:00:22/00:02:37, flags: PT*
>>>> *  Incoming interface: FastEthernet0/0, RPF nbr 10.0.12.2*
>>>> *  Outgoing interface list: Null*
>>>> *
>>>> *
>>>> *(*, 224.0.1.40), 01:26:31/stopped, RP 0.0.0.0, flags: DCL*
>>>> *  Incoming interface: Null, RPF nbr 0.0.0.0*
>>>> *  Outgoing interface list:*
>>>> *    FastEthernet0/0, Forward/Sparse-Dense, 01:26:31/00:00:00*
>>>> *
>>>> *
>>>> *(22.22.22.22, 224.0.1.40), 01:16:47/00:02:37, flags: PLT*
>>>> *  Incoming interface: FastEthernet0/0, RPF nbr 10.0.12.2*
>>>> *  Outgoing interface list: Null*
>>>>
>>>>
>>>>
>>>> Is that the right behaviour? Am I wrong expecting subsequent ping
>>>> answers on R1?
>>>>
>>>> Thanks.
>>>>
>>>> Gian Paolo
>>>>
>>>> _______________________________________________
>>>> For more information regarding industry leading CCIE Lab training,
>>>> please visit www.ipexpert.com
>>>>
>>>>
>>>
>>>
>>> --
>>> Regards,
>>>
>>> Joe Astorino CCIE #24347 (R&S)
>>> Sr. Technical Instructor - IPexpert
>>> Mailto: [email protected]
>>> Telephone: +1.810.326.1444
>>> Live Assistance, Please visit: www.ipexpert.com/chat
>>> eFax: +1.810.454.0130
>>>
>>> IPexpert is a premier provider of Classroom and Self-Study Cisco CCNA
>>> (R&S, Voice & Security), CCNP, CCVP, CCSP and CCIE (R&S, Voice, Security &
>>> Service Provider) Certification Training with locations throughout the
>>> United States, Europe and Australia. Be sure to check out our online
>>> communities at www.ipexpert.com/communities and our public website at
>>> www.ipexpert.com
>>>
>>>
>>>
>>
>>
>> --
>> Regards,
>>
>> Joe Astorino CCIE #24347 (R&S)
>> Sr. Technical Instructor - IPexpert
>> Mailto: [email protected]
>> Telephone: +1.810.326.1444
>> Live Assistance, Please visit: www.ipexpert.com/chat
>> eFax: +1.810.454.0130
>>
>> IPexpert is a premier provider of Classroom and Self-Study Cisco CCNA
>> (R&S, Voice & Security), CCNP, CCVP, CCSP and CCIE (R&S, Voice, Security &
>> Service Provider) Certification Training with locations throughout the
>> United States, Europe and Australia. Be sure to check out our online
>> communities at www.ipexpert.com/communities and our public website at
>> www.ipexpert.com
>>
>>
>>
>> _______________________________________________
>> For more information regarding industry leading CCIE Lab training, please
>> visit www.ipexpert.com
>>
>>
>


-- 
Regards,

Joe Astorino CCIE #24347 (R&S)
Sr. Technical Instructor - IPexpert
Mailto: [email protected]
Telephone: +1.810.326.1444
Live Assistance, Please visit: www.ipexpert.com/chat
eFax: +1.810.454.0130

IPexpert is a premier provider of Classroom and Self-Study Cisco CCNA (R&S,
Voice & Security), CCNP, CCVP, CCSP and CCIE (R&S, Voice, Security & Service
Provider) Certification Training with locations throughout the United
States, Europe and Australia. Be sure to check out our online communities at
www.ipexpert.com/communities and our public website at www.ipexpert.com
_______________________________________________
For more information regarding industry leading CCIE Lab training, please visit 
www.ipexpert.com

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