Routing

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  • 1.  EBGP and IBGP Redistribution

    Posted 09-24-2014 06:30

    Need some clarification here - The default BGP export policy states that BGP will accept all active BGP routes.  Does this include both IBGP and EBGP routes?   I am experiencing an issue where my IBGP routes are not being exported to my EBGP peers.  I have a full mesh IBPG topology,synchronization is off by default, OSPF is my IGP, all peers are up but the router configured for both IBGP and EBGP is not advertising the IBGP routes to its EBGP neighbor.



  • 2.  RE: EBGP and IBGP Redistribution
    Best Answer

    Posted 09-24-2014 07:53

    Hi,

     

     

    Firstly the route learned through IBGP must be active in order to be advertised through EBGP.

     

    Secondly you must take into consideration that by default Junos does not advertise routes back to any EBGP peers that are in the same AS as the originating peer, regardless of the routing instance.

    There is a solution to overcome this behavior which is to use the keyword advertise-peer-as.

     

     

    In any case, use the following command in order to check which routers are being advertised:

    show route advertising-protocol bgp <neighbor-ip-address>

     

     

     

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  • 3.  RE: EBGP and IBGP Redistribution

    Posted 10-01-2014 03:25

    Hi.

     

    As the default policy, BGP always advertise any BGP routes to BGP neighbor. As you say, from IBGP does not advertise to EBGP, it's possible that routes are not active in IBGP (BGP with AD 170 is less prefer than OSP with AD 150 or 10). You can use the command advertise-inactive to override this default.