Content-type: text/html Manpage of DDUPDATE

DDUPDATE

Section: System Administration Utilities (8)
Updated: Last change: Dec 2017
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NAME

ddupdate - Update dns data for dynamic IP addresses

SYNOPSIS

ddupdate [options]

DESCRIPTION

A tool to update dynamic IP addresses typically obtained using DHCP at dynamic DNS services such as Dyndns, Hammernode, Zoneedit or EasyDNS, thus allowing the use a of fixed hostname like myhost.dyndns.org to access a machine. The tool caches the address, and only attempts the update if the address actually changes.

The tool has a plugin structure with plugins for obtaining the actual address (typically hardware-dependent) and to update it (service dependent).

The normal usecase is to specify all commandline options in the config file. However, all options in this file could be overridden by actual command line options e. g., while testing.

Using service providers and possibly also firewalls requires use of username/password credentials. For these, the netrc(5) file is used.

OPTIONS

Options for normal operation:

-H, --hostname <hostname>: Hostname to update, typically fully qualified. Defaults to the not really usable host.nowhere.net
-s, --service-plugin <plugin>: Plugin used to update the dns data for the address obtained from the ip-plugin. Defaults to dry-run, which just prints the address obtained from the ip plugin.
-i, --ip-plugin <plugin>: Plugin used to obtain the actual ip address. Defaults to default-if, which localizes the default interface using heuristics and uses it's address.
-c, --config-file <path>: File containing default values for all command line options. A relative path is interpreted from current directory. See [FILES] below.
-L, --loglevel [level]: Determine the amount of logging information. level is a symbolic syslog level: error,warning, info, or debug. It defaults to warning.
-o, --option <plugin option>: Option interpreted by plugins, documented in --help <plugin>. May be given multiple times as required. Any option on the command line will clear the list of options as of the config file. See PLUGIN OPTIONS.

Other options:

-h, --help [plugin]: Print help. If given a plugin argument, prints help for this plugin.
-l, --list-plugins [ip-plugins|services]: List ip-plugins or service-plugins. By default, lists all.
-v, --version: Print ddupdate version.

PLUGIN OPTIONS

The plugin options are generally just handed to the plugins without any further interpretation. An option is either a single keyword, or a key=value string. No whitespace is allowed in key or value. Commonly used options includes:

firewall=hostname: For ip-plugins plugins retrieving the address from the local firewall. The hostname must normally be present in .netrc to provide username and password.
ip=address: Used by the fixed-address plugin, which uses a hardcoded ip address instead of probing for it.
force: Force an update despite that there is no change compared to the cached address.
proxy=hostname: Use given HTTP proxy when connecting to service provider.
ssl: Use an encrypted SSL connection when connecting to service provider.
timeout=seconds: Timeout when communicating with service provider, defaults to 120 seconds.

PLUGIN LOADING

ddupdate looks for a directory named plugins and tries to load plugins from all files in this directory. The search for plugins is done, in descending priority:

•

In the same directory as the ddclient.py module. This is the development case, and the highest priority.

•

User plugins are in ~/.local/share/ddclient/plugins. Setting the XDG_DATA_HOME environment relocates this to $XDG_DATA_HOME/ddupdate/plugins.

•

The directories /usr/local/share/ddupdate/plugins and /usr/share/ddupdate/plugins. Setting the XDG_DATA_DIRS environment variable relocates these directories according to the freedesktop specification.

EXAMPLES

Please note that the command line options are normally stored in /etc/ddupdate.conf, allowing an invocation without command line options.

Update on dyndns.com using the external address as obtained using the default interface plugin:

        ddupdate -a default-if -p dyndns -H myhost.dyndns.org

Make a debug run without actually updating:

        ddupdate -a default-if -p dry_run -loglevel debug \
            -H myhost.dyndns.org

FILES

.netrc: Used to store username and password for logging in to service providers to update, firewalls to get the IP address etc. See netrc(5) for the format used.
/etc/ddupdate.conf: Default values for all command line options.
/usr/share/ddupdate/plugins: Base directory for upstream plugins.
/usr/local/share/ddupdate/plugins: Base directory for site plugins.
~/.local/share/ddupdate/plugins: Base directory for user specified plugins.
~/cache/ddupdate/*: Cached address from last update with an actual change, one for each update service. Setting the XDG_CACHE_HOME environment variable relocates these files to $XDG_CACHE_HOME/ddupdate/*.

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Time: 19:46:12 GMT, December 25, 2017