First, check if IPv6 is enabled by running the following command. If the output is 0, it means its enabled. If it’s 1, then its disabled already.
cat /proc/sys/net/ipv6/conf/all/disable_ipv6So, to disable ivp6 you need to add the following entries into your /etc/sysctl.conf file
#disable ipv6Moreover it's also a good idea to disable loading of ivp6 module into kernel durning booting, to disable the ivp6 module you need to add following entry into your /etc/modprobe.d/blacklist.conf file
net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1
net.ipv6.conf.lo.disable_ipv6 = 1
# Disable IPV6