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I try to configure two interfaces on my server to behave as independently as possible on the same medium. However I have some problems with ARP (maybe related to ARP flux). I hope somebody can enlighten me?

Server Interfaces on one medium (switch). The following IP addresses are assigned via DHCP.

dev   LL addr  IP addr   
eth0  :01      .83/27
eth1  :02      .92/27

and a route

.47 dev eth0

Client on the same medium (.47) tries to ping the server.

arping .83
-> response from eth0 / :01

arping .92
-> still responses from eth0 / :01

So I turned on arp_ignore

echo 1 > /proc/sys/net/ipv4/conf/eth0/arp_ignore

Now I don't get any response from the server's eth1 anymore... Why am I not getting ARP responses from eth1?

  • ARP Filter is 0 for eth0/eth1/all.
  • Changing the route to eth1 appears to inverse the behavior.
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