We saw this earlier this year after upgrading to a new Linux kernel. The solution for us was to set this in sysctl.conf: net.ipv4.neigh.default.gc_thresh1=0

We saw this earlier this year after upgrading to a new Linux kernel. The solution for us was to set this in sysctl.conf: net.ipv4.neigh.default.gc_thresh1=0 https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1331150/ https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1331150... https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1331150/comments/12 https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1331150...