Reference

`systemd-resolved` behavior map: stub listeners, `/etc/hosts`, LLMNR, mDNS, and routing domains.

This is a practical operator map of the official `systemd-resolved` model. Keep it nearby when host resolution behavior no longer matches what your team expects from legacy `/etc/resolv.conf` assumptions.

Search Resolver TopicsOpen Linux Domain
Key Behaviors

What matters under pressure.

  • The local DNS stub listener normally answers on 127.0.0.53.
  • `/etc/hosts` is still resolved locally and can override network expectations.
  • Single-label names behave differently from multi-label names.
  • Search domains and route-only domains decide which links get queries.
  • LLMNR and mDNS may be involved depending on the name type and interface settings.
Use This Page When

Host lookup behavior becomes inconsistent.

  • Short names fail while FQDNs work.
  • SSH succeeds by IP but not by hostname.
  • The same name resolves differently depending on interface or environment.
  • Application lookups differ from simple shell tests.