Routing

 View Only
last person joined: 3 days ago 

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.  how to check advertised prefix

    This message was posted by a user wishing to remain anonymous
    Posted 02-19-2024 05:39
    This message was posted by a user wishing to remain anonymous

    Hello,

    We have Juniper mx series and we have ~340 BGP neighbours and it is really hard to check which prefixes has been announced to which neighbour, in cisco when we execute sh ip bgp x.x.x.x/y ti will show which neighbours are announcing this prefix, is there anything similiar to this in junper mx series?

    Thank you.



  • 2.  RE: how to check advertised prefix

    Posted 02-19-2024 10:24

    Hello, 

    We use    >show route protocol bgp <prefix> [detail]   command.



    ------------------------------
    WBW,
    Dmitriy
    ------------------------------



  • 3.  RE: how to check advertised prefix

    This message was posted by a user wishing to remain anonymous
    Posted 02-19-2024 12:11
    This message was posted by a user wishing to remain anonymous

    i tried that but it does not show any information about bgp enighbours, it just shows communities, local pref,..




  • 4.  RE: how to check advertised prefix

    Posted 02-20-2024 03:14

    Please write your cisco command in full way by whole words, the cisco command came from IOS/IOS-XE/IOS-XR?



    ------------------------------
    WBW,
    Dmitriy
    ------------------------------



  • 5.  RE: how to check advertised prefix

    This message was posted by a user wishing to remain anonymous
    Posted 02-20-2024 03:52
    This message was posted by a user wishing to remain anonymous

    it is cisco nxos

    Cisco-Nexus# sh ip bgp x.x.138.0/24
    BGP routing table information for VRF default, address family IPv4 Unicast
    BGP routing table entry for x.x.138.0/24, version 276
    Paths: (1 available, best #1)
    Flags: (0x080002) (high32 00000000) on xmit-list, is not in urib

      Advertised path-id 1
      Path type: local, path is valid, is best path, no labeled nexthop
      AS-Path: NONE, path locally originated
        0.0.0.0 (metric 0) from 0.0.0.0 (y.y.y.y)
          Origin IGP, MED not set, localpref 250, weight 32768
          Community: 12345:678

     Path-id 1 advertised to peers:
        172.x.x.17      172.x.x.170

    in the "Path-id 1 advertised to peers" it shows to which peers we are announcing x.x.138.0/24




  • 6.  RE: how to check advertised prefix

    Posted 02-20-2024 04:51

    You can verify advertised routes to a particular neighbor only ((

    1) Verify internal and external peers in a group 

    > show bgp group [detail]
    > show bgp group <group> [detail]

    2) Verify advertised routes to a particular neighbor with their attributes 

    > show route advertising-protocol bgp <neighbor> [detail] 

    > show route advertising-protocol bgp <neighbor> [detail]  | match <prefix>



    ------------------------------
    WBW,
    Dmitriy
    ------------------------------



  • 7.  RE: how to check advertised prefix

    Posted 02-21-2024 05:28

    In addition to Dmitriy's post, you can simply run something like show route advertising-protocol bgp <neighbor IP> <prefix> to check if specific prefix is being advertised to BGP neighbor and what are path attributes of this prefix.

    Also, on receiver side you could run show route receive-protocol bgp <neighbor IP> <prefix>  and show route source-gateway <neighbor IP> <prefix>  to see, with which attributes are prefixes being received from BGP neighbor. Note that first command shows prefixes BEFORE import policy is applied, while second command will show prefix AFTER import policy is applied. For instance, if you are modifying next-hop of incoming prefixes (common situation when 6PE is used), first command WILL NOT show you new next-hop, which the prefix gets after import policy is applied, while second command will show you the final result, which is put into GRIB (or vrf RIB).



    ------------------------------
    FARID AKHUNDOV
    ------------------------------



  • 8.  RE: how to check advertised prefix

    Posted 02-21-2024 10:30

    how to check all neighbors for who is advertising a certain route?  ... sounds like you are wanting a single CLI command that will check all existing bgp neighbors for who is advertising a certain route... I can't find one command that will do that.  I'm not sure if anyone has provided that single CLI command yet  in this thread.  if you find the answer, post it here so I can know as well.

    ...here's a post of someone wanting to know the same thing... 

    https://community.juniper.net/discussion/how-to-show-all-bgp-neighbors-a-particular-route-is-being-advertised-to



    ------------------------------
    - Aaron
    ------------------------------