proper systemd-resolved dns

This commit is contained in:
Casper V. Kristensen 2024-04-05 01:07:48 +02:00
parent 8c777c4e33
commit 557cdc8cb4
2 changed files with 25 additions and 13 deletions

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@ -1,4 +1,4 @@
{...}: {
{config, ...}: {
# https://nixos.wiki/wiki/Networking
# https://nixos.wiki/wiki/Systemd-networkd
@ -10,7 +10,7 @@
# Do not spam dmesg/journalctl with refused connections
logRefusedConnections = false;
};
nameservers = ["127.0.0.53"]; # resolved stub resolver
nameservers = ["159.69.4.2#dns.caspervk.net" "2a01:4f8:1c0c:70d1::1#dns.caspervk.net"];
search = ["caspervk.net"];
};
@ -22,23 +22,35 @@
# systemd-resolved provides DNS resolution to local applications through
# D-Bus, NSS, and a local stub resolver on 127.0.0.53. It implements caching
# and DNSSEC validation. We configure it to only, and always, use
# dns.caspervk.net over TLS. By the way, it's surprisingly hard to get the
# system to always follow the custom DNS servers rather than the
# DHCP-provided ones. Check the traffic with:
# sudo tcpdump -n --interface=any '(udp port 53) or (tcp port 853)'
# dns.caspervk.net over TLS.
# NOTE: It's surprisingly hard to get the system to always follow the custom
# DNS servers rather than the DHCP-provided ones. Check the traffic with:
# > sudo tcpdump -n --interface=any '(udp port 53) or (tcp port 853)'
# or
# > sudo resolvectl log-level debug
# > sudo journalctl -fu systemd-resolved.service
# https://nixos.wiki/wiki/Encrypted_DNS
# https://nixos.wiki/wiki/Systemd-resolved
services.resolved = {
enable = true;
dnssec = "true";
dnsovertls = "true";
# TODO: DNSSEC support in systemd-resolved is considered experimental and
# incomplete. Upstream will validate for us anyway, and we trust it.
# https://wiki.archlinux.org/title/systemd-resolved#DNSSEC
dnssec = "false";
# 'Domains' is used for two distinct purposes; first, any domains *not*
# prefixed with '~' are used as search suffixes when resolving single-label
# hostnames into FQDNs. The NixOS default is to set this to
# `config.networking.search`, which we maintain. Second, domains prefixed
# with '~' ("route-only domains") define a search path that preferably
# directs DNS queries to this interface. The '~.' construct use the DNS
# servers defined here preferably for the root (all) domain(s).
# https://man.archlinux.org/man/resolved.conf.5
domains = config.networking.search ++ ["~."];
# Resolved falls back to DNS servers operated by American internet
# surveillance and adtech companies by default. No thanks, I'd rather have
# no DNS at all.
fallbackDns = ["159.69.4.2#dns.caspervk.net" "2a01:4f8:1c0c:70d1::1#dns.caspervk.net"];
extraConfig = ''
DNS=159.69.4.2#dns.caspervk.net 2a01:4f8:1c0c:70d1::1#dns.caspervk.net
DNSOverTLS=yes
'';
fallbackDns = config.networking.nameservers;
};
# TCP BBR has significantly increased throughput and reduced latency. Note

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@ -4,7 +4,7 @@
# Instead, we enable NetworkManager and the nmtui interface.
networkmanager = {
enable = true;
dns = lib.mkForce "none";
dns = lib.mkForce "none"; # see modules/base/network.nix
};
};