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  • 1.  MX204. Routing problem with directly connected route

    Posted 01-26-2023 03:13


    I need your help!

    I have a problem:

    Configured on one of the interfaces the xx.xx.xx.120/30 network,

    which is part of the larger xx.xx.xx.0/18 network. xx.xx.xx.0/18 is announced to BGP upstreams.

    I do not see from the world a network terminated on one of the router interfaces


    Ping and trace to hosts in the world from the client network and back does not work.


    # show interfaces et-0/0/0
        unit 564 {
            description test_net;
            vlan-id 564;
            family inet {
                filter {
                    input test_filter;
                    output test_filter;
                address xx.xx.xx.121/30;
    # show firewall filter test_filter
    term 1 {
        then accept;
    xx.xx.xx.120/30  *[Direct/0] 1w3d 09:39:31
                        > via et-0/0/0.564
    xx.xx.xx.121/32  *[Local/0] 1w3d 09:39:31
                          Local via et-0/0/0.564
    # show interfaces lo0
    unit 0 {
        family inet {
            filter {
                input filter_to_me;
    # show firewall family inet filter filter_to_me
    term 1 {
        then accept;

    This network advertised to "World":

    # show routing-options static
    route xx.xx.xx.0/18 {
        community [ yyyyy:0 yyyyy:100 yyyyy:110 yyyyy:102 yyyyy:60 ];
    show route advertising-protocol bgp ISP1_peer_ip 
    inet.0: 921682 destinations, 3815557 routes (891246 active, 0 holddown, 587001 hidden)
      Prefix                  Nexthop              MED     Lclpref    AS path
    * xx.xx.xx.0/18         Self                                    I
    ​There are multiple BGP peerings configured on the router from which I get full view.
    Allowed everything on incoming and outgoing policies, but the problem remained.

    I can't understand why my network xx.xx.xx.120/30 isn't working.

  • 2.  RE: MX204. Routing problem with directly connected route

    Posted 01-26-2023 20:18
    For the ping to work in both directions you need to complete the route checks on both sides. 
    • You are sending the prefix xx.xx.xx.0/18
    • Can you confirm with the ISP1_peer_ip route mirror that your prefix xx.xx.xx.0/18 is accepted and installed.
    • Can you confirm you have a local full table or default route out to ISP1_peer_ip for the return traffic
    Also if you have all full tables and multiple ISP you may also be dealing with some asymmetrical routing that might affect results.

    Steve Puluka BSEET - Juniper Ambassador
    IP Architect - DQE Communications Pittsburgh, PA (Metro Ethernet & ISP - Retired)