Linux solution for ARP flux

If for some reason you have to configure multiple network interfaces in the same subnet, e.g. eth0 – 192.168.1.1/24, eth1 – 192.168.1.2/24, eth2 – 192.168.1.3/24, etc., on Linux box you’d certainly face a so called ARP flux issue.
To fix it (I assume you have kernel > 2.6.2) just set the following sysctl options as listed below:

net.ipv4.conf.eth0.arp_ignore = 1
net.ipv4.conf.eth0.arp_announce = 2

In my particular case that wasn’t a complete remedy as I had to amend an additional sysctl parameter:

net.ipv4.conf.ethX.rp_filter = 0

where ethX is your network adapter, e.g. eth0, eth1, eth3, etc.

Read more about arp_announce and arp_ignore options.

Hope that helps. Good luck.

Posted on April 12, 2012 at 11:49 pm by sergeyt · Permalink
In: Linux

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