Well my distro of choice is Ubuntu and currently we are in 10.10, so we need to setup no-ip.org dynamic IP's on our laptop's so when we go to connect to the VPN our firewall can look to see if the IP is authorized before even listening for credentials or certificates.  So here's my notes on getting it installed and configured on Ubuntu 10.10 desktop edition.

Sign up for an account and download the client from

http://no-ip.org

unzip client

Open temrminal and navigate to where you extrated the files

# sudo make install

# sudo ./install

We will need to create a configuration file in /usr/local/etc/no-ip2.confy

# sudo noip2 -c

You need to make this file world readable
# sudo chmod 666 /usr/local/etc/no-ip2.conf

Ok setup is a peice of cake, let's get it running everytime we boot, so no matter where we are at we are good to go
from the zip file copy debian-noip2.sh to /etc/init.dyou need

You need make this file 755 (-rwxr-xr-x)

# sudo chmod 755 /etc/init.d/debain-noip2.sh


Ok cool so it's running at startup, now the only thing is think I've got my time to update set too high on the configuration, but you should be able to change that by stopping th eproccess

# sudo /etc/init.d/debian-noip2 stop

then reconfigure to 1 min intervals or whatever you need

# sudo noip2 -C

Restart the client

#sudo /etc/init.d/debian-noip2 start

That's it, a very simple way of having your Ubuntu 10.10 laptop auto update it's No-ip dynamic dns name.  Now to just add that no-ip name into your firewall or access restrictions and you have another simple layer of security.

PS:  There is also a no-ip.org client for the droid for those of you who ssh into boxes from your droids, this can give you IP restriction based on hostname as well :)