---
name: "ddns3"
section: "1"
platform: "linux"
package: "ddns3-client"
version: "1.8-13"
release: "Debian 10 (Buster)"
platforms: ["linux"]
url: "https://new.carta.tech/ddns3"
---

# ddns3(1)

ddns.nu remote update client

## NAME

ddns3 - ddns.nu remote update client

## SYNOPSIS

**ddns3 --user** *user* **--pass** *password* **\[** *options* **\]** *command* **...**

## DESCRIPTION

**ddns3** updates IP-Handles on the ddns.nu remote update server.  This allows remote automated updates rather than using the website via a browser.

## OPTIONS

- \--user user

  Specifies the username to authenticate with.

- \--pass password

  Specifies the password to authenticate with.

- \--host hostname

  Override the default server hostname to connect to. The default server hostname is  **ns.ddns.nu.**

- \--port portnumber

  Override the default TCP port to connect to. The default TCP port for the ddns3 protocol is **2164**

- \--auth authtype

  Specify what type of authentication protocol to use. The available types are: **plaintext,** **crypt,** **md5,** **ddns,** and **strong.** The default type is **ddns** which is secure in the sense that the username is sent in  cleartext, but the password is sent hashed in such a manner as to defeat replay attacks by utilising a salt sent from the server.

## COMMANDS

- list

  List all IP-Handles and their current values for the account. You may do this multiple times, for example it is perfectly legal (and perhaps even useful) to do a **list,** followed by a **set,** and then another **list** to observe the change.

- set handle-name ip-value

  Set an IP-Handle named **handle-name** to the IP value **ip-value.** Similar to **list** you can specify as many such operations on the command line as you wish and they will be executed in the order specified.

- guess handle-name ip-source

  Set the IP-Handle named **handle-name** to the IP value derived from IP seen by the **ip-source** end of the update connection. The  **ip-source** is specified as either **remote** or **local.** Again you may specify multiple **guess** commands on the command line and they will be executed in order.

  Using the  **local** option saves you from having to specify the IP on the command line. Local guessing usually gets the IP correct as it takes the local address of the socket making the update connection.  With conventional routing arrangements this is likely to be the IP you want.

  However the **remote** option sets the IP-Handle to the IP that the server sees the connection as originating from.  This is most useful if you are running the client from behind a NAT gateway which itself is incapable of running the client. In this case the IP of the NAT gateway is used, rather than the probably martian IP of the host the client is actually executing on.

## DIAGNOSTICS

Useful error messages are produced on stderr, all other runtime output goes to stdout.

On runtime exception the return value of the process may be useful in scripting:

\-1

The usage message was generated by running the command with no arguments.

\-2

The argument parser didn't like the command line.

\-3

A connection could not be established with the update server.

\-4

Authentication failed.

\-5

Network errors closing the connection (these can often be ignored).

\-6

Some kind of internal logic error in the process, like a malloc/free failure.

The process returns a positive count of the number of commands executed on the server that generated an error, or zero on error free completion of all commands.

## BUGS

The authentication details should be read from a file to avoid  their visibility in the process list. There should be support  for other ddns3 protocol primitives like **MOTD** and **HELP** for completeness.  The java implementation  **jddns3** does this, and is largely command line equivalent.  Short network writes are unchecked in at least one place.

## AUTHOR

Alan Yates \<alany@ay.com.au\>

## VERSION

$Id: ddns3.1,v 1.2 2003/03/20 05:21:59 alany Exp $

## SEE ALSO

http://www.ddns.nu/

http://www.ddns.nu/files/ddns-v3.txt