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  1. Bug #1488938
  2. Comment #6

Comment 6 for bug 1488938

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Bogdan Dobrelya (bogdando) wrote : Re: Failure with a kernel panic when the limit of conntrack being hit under load

Update: the arp neighbour cache may be undersized on nodes with many namespaces resulting in thrashing and garbage collection of the ARP table.
The following potential fix should be tested for the 'ping: sendmsg: Invalid argument' and 'net_ratelimit' warning signs:
sysctl net.ipv4.neigh.default.gc_thresh1=1024
sysctl net.ipv4.neigh.default.gc_thresh2=2048
sysctl net.ipv4.neigh.default.gc_thresh3=4096

while current out-of-box values are:
net.ipv4.neigh.default.gc_thresh1 = 128
net.ipv4.neigh.default.gc_thresh2 = 512
net.ipv4.neigh.default.gc_thresh3 = 1024