Routing

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Ask questions and share experiences about ACX Series, CTP Series, MX Series, PTX Series, SSR Series, JRR Series, and all things routing, including portfolios and protocols.
  • 1.  [MP-BGP] - L3VPN route advertisement

    Posted 16 days ago
      |   view attached
    Hi Everyone, 

    I'm currently working on a topic that's a little bit challenging. 

    The Architecture is including only MX-104 Platforms running Junos v.17.1R3.6 on them.

    Architecture : 


    Context :

    On R1,  the LAN 1 is advertised in the two L3PVN Instances (Green and Blue).

    On the other side, we have the R2, that's carrying the L3VPN Instance (Orange). Taking under consideration other requirments, this instance has to mutulise the routes imported form the Green VRF and the Blue VRF. 

    However, the route imported from the VRF Green and VRF Blue is pointing the same LAN (LAN 1). This mean that in the  routing-table of the VRF Orange, we have the same LAN annoced form two different VPNs in routing-table. 

    Questions

    - How could we influence/distinguish at the imoport level of R2, between the same LAN(LAN1) imoported from the two VRFs Green and Blue and make the correspondance with the LAN2 and LAN3  ? 
    - How could we make sure that in case of faillure of one of the VRFs in the router R1, the LAN 2/3 will communicates with LAN 1 that's not impacted by the incident ?  

    Looking formward to hear about your propopasals ! 

    Regards,

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    ABDESSAMED BOURAS
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  • 2.  RE: [MP-BGP] - L3VPN route advertisement

    Posted 14 days ago
    Hi ABDESSAMED BOURAS,

    For orange VRF can you please share the vrf-import policy configuration? LAN1 routes coming from blue and green vrfs will have different RT values. The respective RT values in the route received at R2 can be used to distinguish and influence the routes. E.g. if you want to prefer the route from the blue vrf, then in the import-policy at R2, you can match the Blue vrf's RT and set a higher LP for such routes.

    Regards


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    Sheetanshu Shekhar
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  • 3.  RE: [MP-BGP] - L3VPN route advertisement

    Posted 12 days ago

    is your concern how R2 views the "LAN1" from R1 and the LAN1 on itself (R2)?  if so, I wonder if this is basic, that the route preference will take care of only allowing the best LAN1 subnet into the RIB.... the directly connected LAN1 (preference 0) vice the MP-IBGP learned LAN1 (preference 170)

    https://www.juniper.net/documentation/us/en/software/junos/routing-overview/bgp/topics/concept/routing-protocols-default-route-preference-values.html



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    Aaron Gould
    Senior Network Engineer
    aaron@gvtc.com
    https://www.linkedin.com/in/agould123/
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