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Juniper ex Trace IRB and find Source for ARP requests

  • 1.  Juniper ex Trace IRB and find Source for ARP requests

    Posted 02-01-2021 09:49
    Hi,

    we have two ex9200 and i have an van where i can see many ARP requests from the VRRP of the ex9200 for devices that not online. This device are no more connect to the lan but some device would reach it, because the are in an config of a camera software.

    So i would find out, from wich IP the request sends to another IRB of the ex9200 and than sends out of that camera irb.

    Example: Client X in vlan 3 send a request or packet to his gateway on the ex9200 irb.3  with a destination in irb.40 and intern the ex9200 forward it to his irb.40 and send out on irb.40 the arp request.

    I would to no which ip client X has. Is that possible to trace it on the ex9200?

    Regardes Andre

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    Andre S.
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  • 2.  RE: Juniper ex Trace IRB and find Source for ARP requests

     
    Posted 02-01-2021 19:11
    This command should display both the mac address and associate ip address in the current table.
    show arp

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    Steve Puluka BSEET - Juniper Ambassador
    IP Architect - DQE Communications Pittsburgh, PA (Metro Ethernet & ISP)
    http://puluka.com/home
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  • 3.  RE: Juniper ex Trace IRB and find Source for ARP requests

    Posted 02-02-2021 05:19
    Sorry If i am no understanding you correctly.
    Your trying to find the client in irb.3 vlan that is directly trying to access a device in your irb.40.  Your saying your ex9200 is proxy-arping   Is that correct ?

    If so can  you put a filter on your irb.3 to log  anything in your irb.3 subnet  to the irb.40? 
    example from destination-address  camera-irb.40/32    for example.



  • 4.  RE: Juniper ex Trace IRB and find Source for ARP requests

    Posted 02-02-2021 11:01
    Sorry but it was not so easy ;) I have 300 IRBs where the traffic can came from or there a clients that try to reach irb.40. SO is search fore a trace option to show wahts the irb is doing.

    But i have to solutions found, first i setup i client with one of the dest. IP and take a look in wireshark oder setup the ip on an interface of the ex9200 and make a show monitor traffic on the irb.

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    Andre S.
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