Getting rid of “IPv6 addrconf: prefix with wrong length 56”

Some hosting companies, notably OVH, have their networking set in a way that it constantly “pollutes” dmesg with the following messages:

IPv6 addrconf: prefix with wrong length 56
IPv6 addrconf: prefix with wrong length 56
IPv6 addrconf: prefix with wrong length 56

Here is what you can do to get rid of it.

Add the following to /etc/sysctl.conf and run sysctl -p:

# gets rid of "IPv6 addrconf: prefix with wrong length 56" in dmesg
net.ipv6.conf.eth0.autoconf=0
net.ipv6.conf.eth1.autoconf=0
net.ipv6.conf.all.autoconf=0
net.ipv6.conf.default.autoconf=0