Multicast MPLS VPN on 7200 and 3640

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Jul 29th, 2008
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I was trying to run multicast VPN on 7200 and 3640 routers using dynamips...

Here is my topology:


now at very first i used all router as 3640... and i eanbled PIM SSM on PE1, P and PE2 router...

i have vrf CE with same rd and rt on both the PE1 and PE2 routers...

Core is running IS-IS IGP and PE1 and PE2 has MP-BGP/VPNv4 running... so far everything is working properly...

now I enabled PIM-SM on all core router interfaces including loopbacks... and using PIM SSM to avoid the need for RP...

but when i enabled mdt default under VRF configuration on PE1 and PE2... my tunnel interface is comming up, but i didnt see PE routers as a PIM neighbor for each other via tunnel... and when i did some debug stuff i found it is showing me RPF fail.... (I am using IOS 12.3 for 3640)... Ideally local PE router should be PIM neighbor under the "sh ip pim vrf ce interface" or "neighbor"... so what is that issue is?

but the same setup on 7200 IOS 12.0 is working fine... no any issue...

what it is running fine with 7200 and not with 3640 even i am using same topology and everything?

so finally to remove that RPF fail i used mroute on both PE(3640)... but as a there is only one path to reach PE loopback then why need mroute...?


Devang Patel

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cpubob Tue, 07/29/2008 - 13:55
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In my experience with SSM on dynamips, if it doesn't work at first, save your config and reboot the router. I've have spent hours debugging an issues that a reboot fixed. I am not 100% certain this will work in all instances but controlling the source of the pim messages fixed my issue on a few occasions, using the ip pim register-source command.



devang_etcom Tue, 07/29/2008 - 15:54
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Thanks for your comment... right after writing this post, I tested it on actual 3640 router lab... and it was running good so i guess thats Dynamips issue...

thanks again for your comment and time...


Devang Patel


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