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New Member

L3 MPLS VPN connectivity problem

I´m trying to stablish a L3 VPN like you will see in the scenario attached.

PEs an P are running OSPF like IGP. The routing protocol running between PEs and CEs is RIP.Although CE1 and CE2 knows the remote networks I can´t ping the remote side(like you will see in CE1.txt and CE2.txt). I have been working around it but I can´t get connectivity between CE1 and CE2.I tried with static routes but it still didn´t work.

Thanks in advance for your help about it.

1 ACCEPTED SOLUTION

Accepted Solutions
Silver

Re: L3 MPLS VPN connectivity problem

Hi there,

As you have attached none of the config on PE and P routers, I would have to refer you to do basic troubleshooting of your MPLS network:

http://www.cisco.com/en/US/tech/tk436/tk428/technologies_tech_note09186a0080094b4e.shtml

I did note you are using 3750 switches.. I hope you are using the Metro-version as the ordinary 3750 doesn't support MPLS switching... it just supports VRF-lite in the newer version.. and you should make sure you are using the ES-ports (Gig1/1/1 and Gig1/1/2) as it's these who has the MPLS-support...

Check out this link to the Q&A for the 3750-Metro:

http://www.cisco.com/en/US/products/hw/switches/ps5532/products_qanda_item09186a00801eb822.shtml

Did it help?

6 REPLIES
Silver

Re: L3 MPLS VPN connectivity problem

Hi there,

As you have attached none of the config on PE and P routers, I would have to refer you to do basic troubleshooting of your MPLS network:

http://www.cisco.com/en/US/tech/tk436/tk428/technologies_tech_note09186a0080094b4e.shtml

I did note you are using 3750 switches.. I hope you are using the Metro-version as the ordinary 3750 doesn't support MPLS switching... it just supports VRF-lite in the newer version.. and you should make sure you are using the ES-ports (Gig1/1/1 and Gig1/1/2) as it's these who has the MPLS-support...

Check out this link to the Q&A for the 3750-Metro:

http://www.cisco.com/en/US/products/hw/switches/ps5532/products_qanda_item09186a00801eb822.shtml

Did it help?

New Member

Re: L3 MPLS VPN connectivity problem

Thanks for the reply,

Eventhough it might be truth it is very weird that on both CPs you can see the routes in the routing table trhough redistribution of rip into MP-bgp. We don't have the connections between the ME3750 using the ES ports indeed; are you possitive about the other giga ports not capable of doing mpls features and because of that the fact of not working properly?

Thanks again

Cheers

Mario

Silver

Re: L3 MPLS VPN connectivity problem

Hi there Mario,

I'm pretty sure about that yes... The MP-BGP doesn't need any special ports as it's just logic on a higher level. The ES ports has the HW-support for the processing (imposing/pop'ing/reading etc. etc) of labels used in the MPLS-setup (as well as many other nifty features, Layer2 QoS per VLAN is a cool one).

Could you switch to one of the ES-ports for the link into the P-router?

Did it help?

Re: L3 MPLS VPN connectivity problem

Hi,

are you sure you have a LSP between your PE routers? BGP updates will get through, though only IP is enabled. CE traffic will not, as the VPN label has to reach the remote PE.

Do a

"show ip cef detail" for PE loopbacks. Are there labels inserted? Quick check: extended traceroute between BGP next-hop IP addresses should show labels in the path.

show mpls ldp discovery should give you "xmit/recv" on every MPLS enabled interface.

Make sure to include on every PE/P interface both

mpls label protocol ldp

mpls ip

as in recent versions the default has been changed from TDP to LDP on some platforms.

Hope this helps

Martin

New Member

Re: L3 MPLS VPN connectivity problem

Hi Martin

Thank you very much for your help. I followed Johansen´s advice and it gave us the solution.In this moment the L3 VPN is working well.

Thanks again.

Mario Samper

New Member

Re: L3 MPLS VPN connectivity problem

Hi Johansens

You was right. I changed the connections to the ES ports on the 3750ME Switches today and the VPN is working well in this moment. I have full end to end connectivity.

THANK YOU VERY MUCH FOR YOUR HELP!.WE APPRECIATE IT.

Best regards,

Mario Samper

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