Data-MDT switchover in mVPN

Unanswered Question
Sep 12th, 2009
User Badges:

Hi All,


I tried the following simple topology for mVPN-


CE1-PE1-PE3-CE2


CE1 is connected to the source and CE2 has the receiver.


PE1 & PE3 VRF configuration-

ip vrf CUST1

rd 1:1

route-target both 1:1

bgp next-hop Loopback 0

mdt default 239.192.10.1

mdt data 239.192.20.0 0.0.0.15 threshold 1 list 100

!

access-list 100 permit ip any any

!


I could send the multicast traffic from one end to another using the Default-MDT. PIM adjacency is formed over the MTI Tunnel 0.


The issue is- no matter how much multicast traffic is sent across (multicast traffic here is large ping packets), PE3 does not switchover to Data-MDT.


Please share your thoughts.


Amit.

  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 0 (0 ratings)
Loading.
Laurent Aubert Sun, 09/13/2009 - 02:53
User Badges:
  • Cisco Employee,

Hi Amit,


You don't need the ACL in your case and mdt-data cmd is only required on the PE connected to the source but it can't explain why it's not working.


This is the PIM debug you should have on PE connected to the source:


*Sep 13 10:36:01.683: PIM(1): MDT threshold exceeded for (40.1.1.1,224.1.1.1)

*Sep 13 10:36:01.683: PIM(1): MDT join sent for (40.1.1.1,224.1.1.1) MDT:239.0.0.128 Tunnel0


you could try with a threshold of 5 and see if it change something.


If your source is a router sending ping, please set the timeout to 0


HTH


Laurent.

amit.bhagat Sun, 09/13/2009 - 04:09
User Badges:

Hi Laurent,


The "debug ip pim" command should show Data-join TLVs from the PE router when the traffic for (S,G) entry exceeds the set threshold. But I didn't see any such messages.


Just wondering, did you try this in ur lab? Which routers and IOS did you use? I used 2691 with 12.4(25a) IOS. According to Cisco feature navigator, it supports mVPN.


Regards,

Amit.

Laurent Aubert Sun, 09/13/2009 - 04:19
User Badges:
  • Cisco Employee,

Yes, I tested it with 12.2(33)SRC for 7600 and 12.2(33)SXH for 6500.


Laurent.

ulatif Thu, 09/17/2009 - 16:29
User Badges:

Could you paste the output of following from your configuration on PE1 and PE3:


"show run | i pim"

"show ip pim mdt bgp"



thanks

Usman

amit.bhagat Thu, 09/17/2009 - 16:42
User Badges:

Hi Usman,


show ip pim mdt bgp output is as follows-


PE1# show ip pim mdt bgp

Peer (Route Distinguisher + IPv4) Next Hop

MDT group 239.192.10.1

2:1:1:3.3.3.3 3.3.3.3



Here's another output- It clearly states Default-MDT group is created.


PE1#show ip pim mdt

* implies group is the MDT default group

MDT Group Interface Source VRF

* 239.192.10.1 Tunnel0 Loopback0 CUST1


I dont have the configs at this stage,only had this output handy.


I still need to try Laurent's tip of setting the timeout to 0 since I am send ping packets from a router.


Will update this post once I implement that.

shivlu jain Thu, 09/17/2009 - 22:18
User Badges:
  • Silver, 250 points or more

Hi Amit


The IOS you are using is SRC series and in the outputs you are getting extended community of 2:X:X.

Please let us know have you enabled the ipv4 mdt under bgp or not.


address-family ipv4 mdt

neighbor send-community both

neighbor activate

exit-address-family


regards

shivlu jain

http://shivlu.blogspot.com

amit.bhagat Fri, 09/18/2009 - 06:08
User Badges:

Hi Shivlu,


I have used this IOS on 2691 router-

c2691-spservicesk0-mz.124-25a.bin


Also, I did not enable ipv4 mdt. Most books do not have it enabled, however they could be using older IOS then.


I might have to try enabling ipv4 mdt.


Regards,

Amit.

amit.bhagat Mon, 11/16/2009 - 15:20
User Badges:

Hi All,


Just like to provide an update that this issue was resolved when I switched over to 7200 series routers. I was able to switchover to the Data-MDT as soon as the threshold was reached.


Thank you all.


Regards,

Amit.

ulatif Mon, 11/16/2009 - 21:28
User Badges:

I once had a similar issue in my network where a CPP (control plane policing) policy was dropping the data-MDT joins.

Not saying this is the reason in your case but you might wanna check on these lines:


i.e. whether or not the data MDT join is being generated and makes it through the network while using the 7600/6500

Actions

This Discussion