nxdomain(1)

NXDOMAIN(1) nxdomain man page NXDOMAIN(1)

NAME

nxdomain - simple utility program to clean up hosts files

SYNOPSIS

nxdomain [options] file-in [file-out]

DESCRIPTION

nxdomain is a program that removes dead domains from a host list. The program accepts regular hosts files with IP addresses of 127.0.0.1 or 0.0.0.0, or lists of domain names without IP address, one domain per line. The program is sending a maximum of 30 queries per second. The default upstream resolver is Cloudflare 1.1.1.1.

OPTIONS

--help, -?, -h
Print command-line options and exit.

--chunk=number
Number of domains in a chunk of input data, default 200.

--server=IP_ADDRESS
Use this IP address for your server, default Cloudflare 1.1.1.1.

Other unfiltered servers:
Quad9 - 9.9.9.10
AdGuard - 94.140.14.140

--timeout=seconds
Number of seconds to wait for a response form the server, default 5 seconds.

--timeout-only
Check only the domains that timed out in a previous run.

EXAMPLE

$ nxdomain adblocker.hostsfile adblocker.hostfile.new

LICENSE

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version.

Homepage: https://firejaildns.wordpress.com
Development: https://github.com/netblue30/fdns

SEE ALSO

dnsc(1), fdns(1)

Feb 2026 0.9.76