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no-export community question

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  • 1.  no-export community question

    Posted 27 days ago
    If a router receives a prefix with community no-export, that prefix should be advertised further, right ?

    But I do not understand the following:
    root@vMX-3# run show route receive-protocol bgp 10.30.3.5 extensive 8.8.9.0
    
    inet.0: 39 destinations, 56 routes (39 active, 0 holddown, 0 hidden)
      8.8.9.0/24 (4 entries, 1 announced)
         Accepted
         Nexthop: 10.30.3.5
         AS path: 64513 64516 8888 I
         Communities: no-export
    
    [edit]
    root@vMX-3# run show route advertising-protocol bgp 10.30.33.2 extensive 8.8.9.0
    
    inet.0: 39 destinations, 56 routes (39 active, 0 holddown, 0 hidden)
    * 8.8.9.0/24 (4 entries, 1 announced)
     BGP group underlay type External
         Nexthop: Self
         AS path: [64523] 64514 64524 I
    
    [edit]
    ​

    Why is the prefix 8.8.9.0/24 still advertised further ?

    thanks in advanced !!



  • 2.  RE: no-export community question
    Best Answer

    Posted 26 days ago
    As long as the no-export community is attached to the prefix, it will signal the peer to no advertise the prefix to eBGP peers, the prefix can still be propagated throughout the AS internally. In your case, the community seems to be stripped(?), as it is not in the output.

    Regards,

    Elvin


  • 3.  RE: no-export community question

    Posted 26 days ago
    I figured it out. The route advertised further is learned from other routers. After I applied a correct policy. it works as it should be.

    thanks !!