VPN & DNS Mayhem, Need Help

Just dashing off quick reply for the moment...

The nameserver is the same as your server's hostname. So the nameserver for server.lan will be server.lan. Basically, "what is the name of the machine hosting the DNS records for domain "lan"? Answer: "server.lan".

NB. Put a full stop after the full hostname (including the domain, .lan). E.g....

server.lan.

Next, it needs to know what the IP address is for "server.lan", so it needs an 'A' record which gives the IP address for that hostname.

Finally, the server's network prefs state 127.0.0.1 as it's DNS server and DHCP hands out the server's local IP as the network's DNS server.

Regarding VPN, I've never used the certificate part, only the 'shared secret' method. This will work without a problem - just put the dyndns name into the client as the server address. Obviously you need to port-forward the required traffic from your external IP to you internal server.

First, from your post I don't think you need a DNS server at all. You can set one up if you like for fun, but get everything else working first.

Set up your dyndns account. The free account will not work with "any" domain name, you need to use one of dyndns's registered names. You can pick the hostname, but not the domain. One of the domains they own is "homelinux.net", so I picked my hostname "holybee" and got "holybee.homelinux.net"

Once that is set, the dyndns website will update the DNS records with your new host name and current IP, and it will work until your IP changes. Your IP should stay the same for a few days at least, so you should be able to check that works before proceeding. Most home routers won't respond to a ping, so pinging your new hostname is not a valid test.

You will need to have your router configured to forward the appropriate ports to your internal server. I use VNC, so I have those ports forwarded, and have the screen sharring service turned on. You will need to do this for each service you use (WEB, VPN, VNC, etc)

Once you confirm it works, it will get old (and defeat the purpose of dnydns) when your IP changes and you need to log into the website again to update it. Google for this program and install it "DynDNS Updater.app" It will run in the background as a service. It will detect when you IP changes, then log into dnydns to update the DNS records.

If you have a friend that can be on the phone, it will make much of this easier, as he can test as you are making config changes.

Yipes! I've got DNS, DHCP, VPN, OD, and file and printer sharing services all running on my server after some work. It is critical to get DNS, forward and reverse, operating properly in Snow Leopard Server because so many features rely on it. I couldn't even get Screen Sharing (the mini is headless) to work properly until DNS was correct, even though Screen Sharing to other local systems worked fine!

The server needs to have a static IP on your LAN and unless you intend for it to act as a server on the outside (for which you need a domain name) you need to create a domain name that can't occur on the outside and can't be .local which is used by BonJour on the LAN. Once the DNS service is set up, enabling VPN is straightforward but does require having your router forward the ports.

As mentioned, you can use dyndns.com to map an external domain name to your dynamic external IP address. If you own a domain name, you can have a subdomain point to your dyndns.com assigned external domain name and thus access your home VPN with your domain name at no cost.
Hoffman Labs has a page on setting up the DNS that got me going. Highly recommended! Also the book "Snow Leopard Server for Dummies" which is actually a bit more advanced than its title suggests! Also, I understand that lynda.com has good training on Snow Leopard Server.