How do I configure dynamic DNS when my router does not support it?

Question

I have a MacBook which is connected to the net via an ancient DSL router (NAT enabled). I want to SSH into the server from elsewhere, but my ISP assigns new IP address every once in a while.

I would like to use a dynamic DNS service for "finding" my Mac, but the router does not support any dynamic DNS functionality.

What (lightweight) option is there to update the DNS service with current IP info anyway? I remember installing a clunky menu-bar app several years ago, and I would prefer something configurable from the terminal.

NB: I feel it could be a problem when the MacBook is moved to a different network (friends, company) temporarily and attempts to connect to macbookaddress.dynamicdnz.tld suddenly hit their network. Correct?

Answer 1

ddclient is what I use on my Linux boxes. Works really well.

You can find instructions details here: http://sourceforge.net/apps/trac/ddclient

I think all you would need to do to get ddclient to run is to a @reboot line to your crontab and you’re set.

crontab -e

then add this line:

@reboot /usr/sbin/ddclient -daemon 300 -syslog

Answer 2

You could install the Wide-Area Bonjour preference pane from Apple. Not only will this cause your MacBook to register itself in DNS when you are at home behind your router, but it will do it no matter where you are.

In the prefernce pane you can enter your hostname and the TSIG key the server requires for authenticating dynamic DNS update requests. There is a red light/yellow light/green light widget that shows you whether the dynamic DNS request is failed/in progress/successful.

The software is quite old and has some serious problems such as complete lack of IPv6 support, but it still works with at least basic functionality. There is a link to the source code on the above page in case someone wants to modernize it, but unfortunately the link doesn't lead to the source code.