MPLS Layer 3 VPN PE-CE EIGRP

This topic is to discuss the following lesson:

Thanks for adding these! I have gone through all of the other MPLS videos.

You are welcome Anthony!

very good!

hi Rene ,
Correct order should be as below . The same will apply at PE2. When I try with GNS3 , I only found out that. Again, thanks for enlighten us. Your lessons are simple and clear. Especially QOS and mpls lesson you make me very easy. By the way , please teach us Multicast basic as well. :smiley:

PE1(config)#router eigrp 1
PE1(config-router)#address-family ipv4 vrf CUSTOMER 
PE1(config-router)#autonomous-system 1

Hi Jimmy,

Thanks for sharing this, in my example I used IOS 15 but I didn’t realize that the configuration is slightly different on older IOS versions.

Rene

Rene,

Great lesson, if I need to run EBGP between CE and PE then how can we configure?

Thanks

 

Hamood

Hi Hamood,

In this example I used BGP between the PE and CE:

I will add another example soon with some other BGP PE-CE examples.

Rene

Hi Rene,

Do we have a lesson for EIGRP SoO?

Not yet but I’ll add it soon.

Hi Rene,

So basically you are saying the EIGRP AS number for the VRFs ( not the Global ) on both the PEs and the CEs must be or preferably identical, right ? However the Global EIGRP AS Number for the PEs may or may not be the same and even it could be different from VRF Eigrp AS, Right ?

thx

Ahmad

Hi Ahmad,

The global EIGRP AS number is completely separated from the VRF EIGRP AS numbers. You could use the same or another number, it won’t matter. I would prefer another AS number for global EIGRP just to keep it simple. Just make sure all PE routers use the same global AS number.

Between each PE/CE pair, you have to use the same EIGRP AS number. Like in my example, you can use different EIGRP AS numbers for each PE/CE pair. The only downside is that each CE will then see the routes as EIGRP external. This can be an issue if you have a backdoor link between the two CE sides.

Rene

Hi Rena,
As usual you made it clear ! Thank you for your outstanding support. Ahmad

12 posts were merged into an existing topic: MPLS Layer 3 VPN PE-CE EIGRP

Hi Rene ,

Why the metric for EIGRP is 90 , because this is external.

image

Thx…

Hello Fabio,

Good question, this is something that MPLS VPN does. Here’s an article from Cisco that explains it:

the EIGRP routes in Site 1 are carried through the BGP core network as iBGP routes. The EIGRP routes in “Site 1” and “Site 2” are converted to iBGP routes and EIGRP extended community attributes are appended to the iBGP routes. (See Table 1 for a description of these attributes.) The EIGRP extended community attributes are appended to the EIGRP routes when they are redistributed into BGP as iBGP routes, and VPN routing information is redistributed between the PE routers by multiprotocol BGP.

The routes that originate in “Site 1” travel to the PE router that is connected to the CE router in “Site 2” of the VPN and are then converted back to EIGRP routes using the EIGRP extended community attributes. EIGRP routes are treated the same in “Site 1” and “Site 2.” If the route is internal in “Site 1”, it will be internal in “Site 2”, and if the route is external in “Site 1”, it will be external in “Site 2.” All EIGRP metrics are preserved, and EIGRP metric information, along with the autonomous system, tag, and external data, is carried across the VPN over the BGP core network.

EIGRP routes are converted to iBGP routes on the PE router by appending EIGRP extended community attributes. The PE router uses multiprotocol BGP to distribute the VPN routing information using the these extended community attributes. The BGP routes are converted back to EIGRP routes using the extended community attribute information when the iBGP routes reach the PE router that is connected to the destination CE router.

Hope this helps!

Rene

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Any luck on the EIGRP SoO lesson yet Rene? :wink:

Cost Communities are actually a huge part of MPLS VPN.

The lessons idea button doesn’t seem to be working btw.

Hello Chris…

Hmm, I’ll let @ReneMolenaar know about the malfunctioning Submit Ideas button… Thanks for the heads up…

Laz