function ipv6-ctrl --description 'Disable or enable IPv6 support.'
    if [ $(sysctl -n net.ipv6.conf.all.disable_ipv6) -eq "0" ];
        sudo sysctl -w net.ipv6.conf.all.disable_ipv6=1
        sudo sysctl -w net.ipv6.conf.default.disable_ipv6=1
    else;
        sudo sysctl -w net.ipv6.conf.all.disable_ipv6=0
        sudo sysctl -w net.ipv6.conf.default.disable_ipv6=0
    end
end