1.6 KiB
1.6 KiB
systemd-resolved additional config files
Files explained
- 00-defaults.conf - configuration not touching resolvers. Disables DNSSEC (as systemd-resolved doesn’t handle it properly), enables opportunistic DoT and caching.
- dot-*.conf - configuration to use the DNS provider with
DNS-over-TLS. If captive portals are a concern,
DNSOverTLS
. - README.md - you are reading it right now.
General commentary
- Based on my test DNSOverTLS is not supported in Ubuntu 18.04.x LTS
(however at the time of writing this README.md, the current version is
Ubuntu 20.04.0) (systemd v237). DNSOverTLS became supported in v239,
strict mode (yes) in v243 (big improvements in v244).
- TODO: find out when SNI became supported, I have just spotted it in the fine manual in 2020-06-??.
- Domains has to be
.~
for them to override DHCP. See https://www.internetsociety.org/blog/2018/12/dns-privacy-in-linux-systemd without which I wouldn’t have got this right. - DNSSEC may not work if the system is down for a long time and not
updated. Thus
allow-downgrade
may be better for non-tech people, even with the potential downgrade attack. There are also captive portals, affectingDNSOverTLS
. Both takeyes
orno
or their own special option, for DNNSEC theallow-downgrade
, for DNSOverTLSopportunistic
.
Other links I have found important and my files are based on:
- https://wiki.archlinux.org/index.php/Systemd-resolved
- request for strict DOT: https://github.com/systemd/systemd/issues/10755
- vulnerable to MITM: https://github.com/systemd/systemd/issues/9397