Disable ipv6 vim /etc/sysctl.conf # insert net.ipv6.conf.all.disable_ipv6 = 1 net.ipv6.conf.default.disable_ipv6 = 1 net.ipv6.conf.lo.disable_ipv6 = 1 # reload config sysctl -p Enable listening on low port number without root permissions sysctl net.ipv4.ip_unprivileged_port_start=0