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865 Views 1 Reply Latest reply: Dec 20, 2011 9:07 PM by Scott Morris - CCDE/4xCCIE/2xJNCIE RSS

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MPLS VPN

Dec 20, 2011 3:55 PM

Andre 47 posts since
Aug 16, 2011

Hi everybody,

 

Im creating a scenario where I have 2 different companies (company A and Company B) being connected using MPLS VPN.  Site A1 should talk to Site A2 and Site B1 should talk to Site B2, and at the same time Site A1 should talk to Site B1 but Site A2 cannot talk to B2 and vice-versa.

 

All the things I configured is working pretty nice with the following RD and RT:

 

R1_PE#
ip vrf A
rd 1:1
route-target both 1:1
route-target both 1:3

 

ip vrf B
rd 1:2
route-target both 1:2

 

R2_PE#

ip vrf A
rd 1:1
route-target both 1:1

 

ip vrf B
rd 1:2
route-target both 1:2
route-target both 1:3

 

 

RT (1:1) is for A1 and A2 to have a talking
RT (1:2) is for B1 and B2 to have a talking
RT (1:3) is for A1 and B2 to have a talking

 

At that point all the things r working perfectly (CE-PE routing is good) but what Im seeing strange is the following:
Site A1 - lo0: 3.3.3.3 255.255.255.255 and lo1: 20.20.20.1 255.255.255.0

Site A2 - lo0: 5.5.5.5 255.255.255.255 and lo2: 30.30.30.1 255.255.255.0

 

Site B1 - lo0: 4.4.4.4 255.255.255.255 and lo1: 20.20.20.2 255.255.255.0

Site B2 - lo0: 6.6.6.6 255.255.255.255 and lo2: 30.30.30.2 255.255.255.0

 

When I go to Site A1 and ping 30.30.30.1 and 5.5.5.5 and 6.6.6.6 it successfully pings, but it fails when I ping 30.30.30.2
The same in Site B1 when I ping 4.4.4.4 and 3.3.3.3 and 30.30.30.2 it successfully pings, but it fails when I ping 30.30.30.1

 

Please, I wanna understand why those pings are failing... I tried to create loopback interfaces on both sites and it pings successfuly.

 

Would it be that are 30.30.30.2 and 30.30.30.1, as well as 20.20.20.2 and 20.20.20.1 are creating conflict, just like the router does not know which vlan tag to impose to it, and then discard the packet?????? Since, all different loopback interfaces are pinging without any problem.

I look forward to hearing from you guys...

  • Scott Morris - CCDE/4xCCIE/2xJNCIE 8,398 posts since
    Oct 7, 2008
    Currently Being Moderated
    1. Dec 20, 2011 9:07 PM (in response to Andre)
    Re: MPLS VPN

    Who has which routes?

     

    R1-A - Knows how to get to R2-A and R2-B (but not R1-B)

    R1-B - Knows how to get to R2-B (but not R1-A or R2-A)

    R2-A - Knows how to get to R1-A (but not R1-B or R2-B)

    R2-B - Knows how to get to R1-A and R1-B (but not R2-A)

     

    Remember that RD has nothing to do with RT.  RD is part of your VPNv4 information.  RT is an extended community value.

     

    So you have to decide what you will import into your local table.  You need to know the route out to something, and you need to know the route back from something. 

     

    HTH,

     

    Scott

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