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VSX arp debuging

Question asked by Dor Marcovitch on May 29, 2018
Latest reply on May 30, 2018 by Dor Marcovitch

hey,

 

i have 2 VSs on the VSX which are sharing the same external subnet (connected to the same vSwitch)

in addition each VS has it's own public subnet, meaning the upstream router has route to network X to VS1 and route to network Y to VS2.

i have internal client on VS1 that i hide behind ip from subnet X. this client fails to access the internet. i can see only icmp request , without reply.

when i hide it behind the VS1 ip it has internet.

further checks revealed that the upstream router has a lot of logs of arp flapping for the public ip of VS1.

when i have checked those MAC address it seams that they match to the wrp interface of VS1 and VS2 which faces the upstream router, which is weird.

checking tcpdump on VS2 for arp packets, i could see that for some reason VS2 sends arp reply for VS1 public ip with it's public interface MAC address..

this situation can be caused by

  1. VS2 has interface with this IP
  2. NAT is configured on VS2 with this IP
  3. local.arp was configured manually with this IP and MAC

non of the above is configured on this environment.

 

  1. anyone has direction?
  2. which service is responsible for ARP?
  3. how do i debug the FW to get the reason for it?

i am using R80.10

thanks

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