Stop the Kernel Logging ipv6
To disable IPv6 on all interfaces system wide
sudo vi /etc/sysctl.conf
add this line
net.ipv6.conf.all.disable_ipv6 = 1
Or To disable IPv6 on an interface only
net.ipv6.conf.lo.disable_ipv6 = 1
net.ipv6.conf.eth0.disable_ipv6 = 1
sudo sysctl -p /etc/sysctl.conf or reboot