DYNDNS(9)           XR32 REFERENCE MANUAL                 9/3/2013

NAME
        DYNDNS -- Dynamic DNS Update Client.

DESCRIPTION
 More and more people these days have dynamic IP addresses,
 i.e. IP addresses which are assigned by their Internet Service
 Provider and which may be different each time they log on.
 Broadband users are permanently connected to the internet, but
 even their IP addresses may be changed at any time by the ISP,
 unless they pay extra for a static address.

 For the normal internet user this is not a problem, because
 no-one else needs to know their IP address. However, if you
 want other people to be able to connect to your system, e.g.
 if you are running a web server, they need to know your
 current IP address. This is where the dynamic DNS providers
 come in.

 There are many organisations providing dynamic DNS services,
 one of whom is DYNDNS.ORG. It is easy, and free, to set up an
 account with dyndns.org, and after doing so you may choose one
 or more hostnames for your system, for example "g8pzt.ath.cx".

 All you then have to do is keep dyndns.org informed of your
 current IP address, either manually or using an automatic
 update client. Whenever someone asks their system to connect
 to "g8pzt.ath.cx", they are given its current IP address.

 Xrouter has an integral client for automatically maintaining
 dynamic DNS entries at dyndns.org, thus obviating the need to
 run an external client or perform manual updates.  If the
 client is enabled, and your IP address changes, the client
 will update one or more hostname entries on the dyndns.org
 DNS server.  If you do not use dynamic dns, you need read no
 further.

 The client is enabled by including the directive DYNDNS=1 in
 the relevant PORT configuration block in XROUTER.CFG, i.e. the
 port which is connected to the Internet. DYNDNS=0 disables the
 client, as does omitting the directive altogether.  Note: you
 must only use this directive on ONE port, and you may crash
 XRouter if you try to use it on more than one.

 The client requires a configuration file, DYNDNS.CFG, and it
 creates a data file DYNDNS.BIN. The configuration file is
 heavily commented, so it should be self-explanatory.

 If your Xrouter is *directly* connected to the Internet, i.e.
 via a PSTN modem or non-routing cable modem, the client simply
 monitors the port IP address (which is assigned by the ISP
 using IPCP or DHCP), and tells dyndns.org when it changes.
 This mode is selected by putting "NO" on the "Use external IP
 detection service" configuration line in DYNDNS.CFG.

 However, if your connection to the Internet is via a NAT
 router such as an ADSL modem/router or Windows ICS, the port
 IP address will be a "private" one which no-one else could
 access. In this case, the client can be configured to query an
 external IP address detection service at regular intervals,
 updating dyndns.org if a change is detected. This mode is
 selected by putting "YES" on the "Use external IP detection
 service" configuration line.

 Free accounts on dyndns.org are removed if they haven't been
 updated for 35 days.  Thus, if your IP address hasn't changed
 for 30 days, the client automatically sends an update to keep
 the account refreshed.

 You may have more than one hostname associated with your IP
 address, but that's not a problem.  In the "hostname(s) to be
 updated" line, simply list the hostname, separated by commas.
 Be careful not to include any spaces or mistakes in the line.

FILES
        DYNDNS.CFG -- Configuration file

DYNDNS(9)                 END OF DOCUMENT