On 4 October 2017 at 07:20, Phil Perry <pperry at elrepo.org> wrote: > On 04/10/17 03:46, Phil Manuel wrote: > >> Hi, >> >> If I disable ipv6 via the kernel command line, ipv6.disable=1, then >> systemd-networkd fails to bring up any interfaces. >> >> Removing the option and networking works as expected. >> >> Phil. >> > > How are you controlling your network interfaces? I am using NM. > > Whilst not answering your question directly, I disable ipv6 in > /etc/sysctl.conf. > > cat /etc/sysctl.conf > # sysctl settings are defined through files in > # /usr/lib/sysctl.d/, /run/sysctl.d/, and /etc/sysctl.d/. > # > # Vendors settings live in /usr/lib/sysctl.d/. > # To override a whole file, create a new file with the same in > # /etc/sysctl.d/ and put new settings there. To override > # only specific settings, add a file with a lexically later > # name in /etc/sysctl.d/ and put new settings there. > # > # For more information, see sysctl.conf(5) and sysctl.d(5). > net.ipv4.ip_forward = 1 > net.ipv6.conf.all.disable_ipv6 = 1 > net.ipv6.conf.default.disable_ipv6 = 1 > > After updating, run 'sysctl -p' and 'dracut -f' > > > > He's using systemd-networkd as he stated. Best advice? Don't disable IPv6 ... configure your firewall properly. Too much now depends on IPv6 to play silly buggers with a key component of the network stack (eg default binds and network bonding).