VRF route target

[AlirezaTorkashvand]

I have a question in configuration the MP-VRF-MPLs scenario 

when I configure the scenario in site to site of P2P is easy because you configure the RTs for source and des and configure it in the other side in opposite site 

but in different scenario how I should configure the Rt export and import because there are more that one Dest and sides 

for example in this scenario I have three sides of BGP and the middle router as route reflector 
how I should configure the vrf RT and extera stiff..

Tank you

[MHM Cisco World]

RR not modify the RT. 

So in each VRF config different RT and use route-target both (merge import and export in one number)

and it will be OK 

NOTE:- if you use same RT for all sites and there is RR then there is issue since the RR send by defualt only best path  for one prefix.

MHM

[AlirezaTorkashvand]

Thank you for your help

So, what is the solution when I have multiple sites and I want run the configuration on BGP i can not configure all the connections site to site 

Thanks 

[MHM Cisco World]

[AlirezaTorkashvand]

I have two VRfs : Bank and Bit and in each Pe I have configured one of them on each interface

[MHM Cisco World]

Only write vrf in each PE (1 and 2) and PE of HQ  in topology and I will share RT you need 

MHM

[M02@rt37]

@AlirezaTorkashvand 

When managing multiple sites in an MP-BGP MPLS-VPN scenario, configuring site-to-site connections for every pair of sites becomes complex and unmanageable as the number of sites increases.

A scalable solution is to use a centralized design with a Route Reflector (RR) or hub-and-spoke topology. In this model, each site establishes an iBGP session with the hub (RR), which simplifies the configuration and eliminates the need for direct site-to-site peering. Route Targets are used to control route distribution: export RTs define what routes a site advertises, while import RTs control which routes a site accepts.

For any-to-any communication, a common RT can be configured across all sites, enabling full-mesh connectivity through the RR without manual site-to-site configurations. Alternatively, predictable RT patterns can be used for dynamic RT assignment based on the VRF or RD.

When MPLS Layer 3 VPNs are in place, Provider Edge (PE) routers handle route propagation, further simplifying the setup.

[M02@rt37]

Hello @AlirezaTorkashvand  

Start by assigning unique Route Targets for each VRF's export and import configuration. For instance, you can assign 65001:1 as the export RT for Site A, and 65001:2 and 65001:3 as import RTs for Site A to receive routes from Sites B and C. Similarly, Site B can export routes with 65001:2 and import routes with 65001:1 and 65001:3, while Site C uses 65001:3 for exports and imports routes with 65001:1 and 65001:2. This approach ensures that all sites can communicate with each other while keeping routes isolated to the intended VRFs.

The VRF configuration on each PE router reflects these RT assignments. For example, on the PE serving Site A, you would define the VRF with its Route Distinguisher (RD) and configure it to export 65001:1 and import 65001:2 and 65001:3. This ensures that routes exported by Site A are correctly marked with its RT and that it imports routes from the other sites by matching their export RTs.

If the middle router acts as a route reflector, it only needs to propagate the routes between the PE routers without making changes. The key is ensuring that each VRF is correctly configured on its respective PE so that the route reflector can facilitate communication seamlessly. This strategy works well for multi-site scenarios because it is scalable, and you can extend it to additional sites by defining new RTs and updating the import/export policies accordingly.

[AlirezaTorkashvand]

It did not worked 
I think there is a problem with the RR 

because I have configured this scenario with two sites and there were no problem with it but with route reflector there is problem.

and my RR is okay when I advertise a network in global BGP the network advertises and all routers take it 

I have to find the problem with RR and fix it