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Default route-target filter

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  • 1.  Default route-target filter

    Posted 04-30-2018 09:08
    Hi All, Is there such a thing as a 'bgp default route-target filter' in Junos? (MX960 router running Junos 12.3) i.e.: will the router reject inet-vpn address-family routes with an RT for which the router doesn't have a vrf-instance configured to import routes with that RT? I'm thinking of the instance whereby the router is used as an ASBR for a Type B NNI (inter-AS MPLS VPN); the ASBR (which is a client of a VPN-RR within it's own AS) doesn't have vrf-instances configured but it is required to announce inet-vpn address-family routes to another ASBR (in another AS) via MP-eBGP ... if there is such a thing as a 'bgp default route-target filter' then it would need to be disabled in order to allow the ASBR to import the inet-vpn routes from the VPN-RR and then announce them to the other ASBR via MP-eBGP ... TIA


  • 2.  RE: Default route-target filter
    Best Answer

    Posted 04-30-2018 11:09

    Hello,

    Two scenarios:

    1/ If "family route-target" is not enabled, the default RT filter does not exist. 

    2/ If "family route-target" is enabled and negotiated, the default RT filter is the set of individual /96 RT NLRI derived from locally configured VRF. Specifically, /96 RTs are derived from VRF import policies or "vrf-target|vrf-target import" line(s) of config inside each routing-instance of "type vrf".

    You can override/ehnance scenario #2 with locally-configured static RTs to attract inet-vpn routes for VRFs that do not exist locally:

    https://www.juniper.net/documentation/en_US/junos/topics/usage-guidelines/vpns-configuring-static-route-target-filtering.html

    HTH

    Thx

    Alex

     

     



  • 3.  RE: Default route-target filter

    Posted 05-01-2018 01:10
    Very helpful - many thanks