VPN connection fails

In http:Q_27504876.html and similar the solution was checking the new certificate and using it's full cn, including ant trailing full stop.

I read the article,  but I still do not understand what the problem is and how to fix it.

To view certificates
http://msdn.microsoft.com/en-us/library/ms788967(v=vs.110).aspx
In details examine the issuer and subject
Is that your domain's root certificate authority (or was it different for the 2003 server when it was set up)
A full set of cert requirements is at
http://technet.microsoft.com/en-gb/library/cc759575(v=ws.10).aspx#cert_req
If the root ca has changed, with the client on the domain lan
http://technet.microsoft.com/en-gb/library/cc757207(v=ws.10).aspx
howto update the certs on the client off the lan over http
http://www.isaserver.org/img/upl/vpnkitbeta2/vpnclienteap.htm

I noticed that Virtual Private Network on SBS2011 Console/Connectivity. So I decided to activate that and changed port forwarding to the IP address of SBS2011 computer.
Now it works.

I thought you are not supposed to run RRAS on the domain controller. In fact I remember running into a big problem when trying to activate RRAS on Windows 2008 Domain Controller.  I had to call Microsoft Engineer to resolve/clean up the mess that I created. He told me not to activate RRAS on DCs.

Going back to yesterday, I tried another W2003 Server as VPN/RRAS, but to no avail.  All the PCs that I manage on the network are already joined the domain.
It has been working fine for years too.
The only thing that I can see different is that SBS Certificate has expired.

That said, is it ok to use SBS2011/DC as VPN server? If it is not a good idea, Microsoft would not have made it available on SBS Console ... but then I am not sure if it is such a good idea based on my experience in the past.

It works.  SBS allows several things normally not recommended.
Sorting the expired certificate on the 2k3 machine remains painful to fix.  Review the system and application logs for related errors as (if that identifies the problem)with the given eventid we may be able to request a hotfix.  Have root cert updates been applied to the 2k3  machine ond were there errors importing the cert?

@Joseph
"Have root cert updates been applied to the 2k3  machine ond were there errors importing the cert? " --> Yes I ran new certificate (generated by SBS2011 Console) on W2003 VPN Server, but the same problem.

What I will do is set up W2003 server (Virtual Machine in VMWare host)  on a separate network with PUBLIC IP and VPN into it directly.  I will post the result.

Mark your own post as the solution, and keep the points.

I discovered that I can turn SBS2011 server as a VPN server and it actually worked.