2024.02.02
No Such Host

No Such Host

Fixing “Startup failed: proxy: udp: listen udp: lookup localhost on :53: no such host” Error.

Startup failed: proxy: udp: listen udp: lookup localhost on <ip>:53: no such host

This indicates that a program trying to start encountered an issue resolving the hostname localhost on port 53, which is typically used for DNS lookup. For example, I got an error when trying to start NextDNS service on my computer.

Feb 16 21:53:01 void systemd[1]: Started NextDNS DNS53 to DoH proxy..
Feb 16 21:53:01 void nextdns[593]: Starting NextDNS 1.42.0/linux on localhost:53
Feb 16 21:53:01 void nextdns[593]: Listening on TCP/localhost:53
Feb 16 21:53:01 void nextdns[593]: Listening on UDP/localhost:53
Feb 16 21:53:01 void nextdns[593]: Network not yet ready, waiting
Feb 16 21:53:01 void nextdns[593]: Listening on TCP/localhost:53
Feb 16 21:53:01 void nextdns[593]: Listening on UDP/localhost:53
Feb 16 21:53:01 void nextdns[593]: Network not yet ready, waiting
Feb 16 21:53:01 void nextdns[593]: Listening on TCP/localhost:53
Feb 16 21:53:01 void nextdns[593]: Listening on UDP/localhost:53
Feb 16 21:53:01 void nextdns[593]: Network not yet ready, waiting
Feb 16 21:53:02 void nextdns[593]: Listening on TCP/localhost:53
Feb 16 21:53:02 void nextdns[593]: Listening on UDP/localhost:53
Feb 16 21:53:02 void nextdns[593]: Network not yet ready, waiting
Feb 16 21:53:02 void nextdns[593]: Listening on TCP/localhost:53
Feb 16 21:53:02 void nextdns[593]: Listening on UDP/localhost:53
Feb 16 21:53:02 void nextdns[593]: Network not yet ready, waiting
Feb 16 21:53:04 void nextdns[593]: Listening on TCP/localhost:53
Feb 16 21:53:04 void nextdns[593]: Listening on UDP/localhost:53
Feb 16 21:53:04 void nextdns[593]: Startup failed: proxy: udp: listen udp: lookup localhost on <ip>:53: no such host
Feb 16 21:53:04 void nextdns[593]: Error: proxy: udp: listen udp: lookup localhost on <ip>:53: no such host
Feb 16 21:53:04 void systemd[1]: nextdns.service: Main process exited, code=exited, status=1/FAILURE
Feb 16 21:53:04 void systemd[1]: nextdns.service: Failed with result 'exit-code'.

Workarounds

If you’re utilizing systemd, consider disabling systemd-resolved as it could potentially interfere with the solution outlined below. This step grants more control over network configuration.

> cat /etc/hosts
# Static table lookup for hostnames.
# See hosts(5) for details.

If your /etc/hosts file lacks configuration, similar to the output above, insert the following code into it:

127.0.0.1   localhost
::1         localhost
127.0.1.1   yourhostname.localdomain  yourhostname

Ensure that the /etc/hosts file appears as follows after insertion:

> cat /etc/hosts
# Static table lookup for hostnames.
# See hosts(5) for details.

127.0.0.1   localhost
::1         localhost
127.0.1.1   yourhostname.localdomain  yourhostname

The issue should be resolved, and the program should start without encountering the previous error messages.

Feb 16 22:05:09 void systemd[1]: Started NextDNS DNS53 to DoH proxy..
Feb 16 22:05:09 void nextdns[6231]: Starting NextDNS 1.42.0/linux on localhost:53
Feb 16 22:05:09 void nextdns[6231]: Listening on TCP/[::1]:53
Feb 16 22:05:09 void nextdns[6231]: Listening on TCP/127.0.0.1:53
Feb 16 22:05:09 void nextdns[6231]: Listening on UDP/[::1]:53
Feb 16 22:05:09 void nextdns[6231]: Listening on UDP/127.0.0.1:53