Essential configuration for new installations

This page describes some essential configuration to get a new installation ready for basic use with support for networking.

Time

timedatectl set-timezone Europe/Amsterdam
timedatectl set-ntp yes

Locale

tee -a /etc/locale.gen > /dev/null <<EOF
en_US.UTF-8 UTF-8
EOF

locale-gen
localectl set-locale LANG=en_US.UTF-8

next to en_US.UTF-8 UTF-8, you can als install more locales like: en_US ISO-8859-1, nl_NL.UTF-8 UTF-8, nl_NL ISO-8859-1 and nl_NL@euro ISO-8859-15

Networking

Set the hostname

hostnamectl set-hostname Arch

Enable basic networking

For simple DHCP networking with systemd-networkd, do:

tee /etc/systemd/network/physical.network <<EOF
[Match]
Name=e*
[Network]
DHCP=yes
EOF

systemctl enable --now systemd-networkd

This assumes that the names of network devices comply with pattern e* which supports predictable network interface names like i.e. eno1, ens1 and enp2s0 as well as unpredictable kernel-native ethX names like eth0.

Enable Hostname Resolution

systemctl enable --now systemd-resolved
ln -sf /usr/lib/systemd/resolv.conf /etc/resolv.conf

mDNS

To add support for mDNS (for hosts in the .local domain), add MulticastDNS=yes to the [network] part of your .network file(s) (i.e. /etc/systemd/network/physical.network) and systemctl restart systemd-networkd.

single-lable lookups

To be able to resolve signle-lable names (without a dot in it), you can either use LLMNR or your own DNS server (like dnsmasq). In the case of using LLNMR, no adaptations are necessary because systemd-resolved supports it out-of-the-box. When you’d like to use your own DNS server, you need to do the following:

1. Disable LLMNR in systemd-resolved
2. Tweak /etc/nsswitch.conf to continue looking up single-lable lookups by using dns
3. Disable DNSSEC in systemd-resolved when you trust your own DNS server
4. Restart systemd-resolved

Disable LLMNR

To my taste, LLMNR nterferes too much which single-lable lookups by DNS. To disable LLMNR in systemd-resolved, do the following:

tee -a /etc/systemd/resolved.conf <<EOF
LLMNR=no
EOF

Tweak /etc/nsswitch.conf

According to https://wiki.archlinux.org/index.php/systemd-networkd#systemd-resolve_not_searching_the_local_domain, systemd-resolve may fail to resolve single-lable names by DNS in which case [!UNAVAIL=return] should be removed from /etc/nsswitch.conf’s hosts: line.

Disable DNSSEC

When you trust your own DNS server, you can disable DNSSEC as follows:

tee -a /etc/systemd/resolved.conf <<EOF
DNSSEC=no
EOF

Please check my recommended supplements to get a more functional system.