Routing

 View Only
last person joined: 2 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.  Can anyone verify my assumption related to BGP peer address ?

    Posted 03-04-2021 20:13
    If I need to establish eBGP with a remote site, but I have no information about which my local address the remote site is using. Can I assume the remote site is using either my loopback address or the direct interface address facing to the remote site, no third address is possible to be used ?

    thanks a lot in advance !!


  • 2.  RE: Can anyone verify my assumption related to BGP peer address ?

    Posted 03-04-2021 22:54
    Is this a directly connected eBGP peer? If so, your directly connected IP facing this peer more often than not. However, if this is a multihop session it could also be using a route toward your loopback IP. 

    If the remote eBGP peer is already configured, you should be able to use traceoptions and sniff out what the eBGP peer is configured to peer with IP wise. 

    set protocol bgp traceoptions flag packets detail 
    set protocol bgp traceoptions file bgp-find-ip


  • 3.  RE: Can anyone verify my assumption related to BGP peer address ?

    Posted 03-05-2021 00:19
    thanks so much !!

    If the remote site uses allow commands,  then I will try to peer with it via my loopback IP or the interface IP to see which one can establish the neighbor,  that is enough. Or any other way I can use ?


  • 4.  RE: Can anyone verify my assumption related to BGP peer address ?
    Best Answer

    Posted 03-05-2021 08:43
    As I said above you could try both direct and loopback sure. Or use trace options to Try and view the packets of which AS and IP the remote peer is trying to peer with.


  • 5.  RE: Can anyone verify my assumption related to BGP peer address ?

    Posted 03-05-2021 09:26
    thanks so much !!!