---
name: "ip2host"
section: "1"
platform: "linux"
package: "ip2host"
version: "1.13-2.1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/ip2host"
---

# ip2host(1)

## NAME

```
  ip2host - Resolves IPs to hostnames in web server logs
```

## SYNOPSIS

```
  ip2host [OPTIONS] [cache_file] < infile > outfile
  infile  - Web server log file.
  outfile - Same as input file, but with IPs resolved to hostnames.
  Options:
  --children=...  Number of child processes to spawn (default: 40)
  --timeout=...   Seconds to wait on DNS response (default: 20)
  --buffer=...    Maximum number of log lines to keep in
                  memory (default: 50000)
  --flush=...     Number of lines to process before flushing
                  output buffer (default: 500)
  --cache=...     Filename to use as disk cache (default: none)
  --ttl=...       Number of seconds before IPs cached on disk are expired
                  (default: 604800 - One week)
  --ipv6          Match IPv6 addresses too
  --regex=...     Perl regular expression to match IP
```

## DESCRIPTION

This is a faster, drop-in replacement for the logresolve utility distributed with the Apache web server.

It's been reported to work under Linux, FreeBSD, Solaris, Tru64, and IRIX.

## AUTHOR

Maurice Aubrey \<maurice.aubrey+ip2host@gmail.com\>

Based on the logresolve.pl script by Rob Hartill.

## COPYRIGHT

Copyright 1999-2012, Maurice Aubrey \<maurice.aubrey+ip2host@gmail.com\>.

This module is free software; you may redistribute it and/or modify it under the same terms as Perl itself.

## README

Resolves IPs to hostnames in web server logs. This is a faster, drop-in replacement for the logresolve utility distributed with the Apache web server.

## SCRIPT CATEGORIES

Web