Windows Server 2003 Server RDP

Do another types of connectivity (i.e. http or just ping) to this server work properly during RDP outages?

No this is a server we want to host some VM's, which then we launch on it, and use the host as a jump box.

As this is a development server, we only have RDP open, everything else is locked down on the firewall.

Well, for first, everytime the RDP fails, the server is still online?
Have a look on your Network connection, what type of connection are you using on VMWARE?
Do you have a DHCP server running on your network?

Sorry for the questions, but best way to help you, is knowing what you have.

Try to open something else... Just to check it's server side problem related to RDP or something with connectivity.

I have opened a few ports so that I can go straight through the host to the VM
Ie, 192.168.1.1:280.

At the moment the server is on a desk by us, we are looking at moving it, but want this to be working first, and because of this can confirm it is online.
The issues with the RDP is just on the actual host server, but within the VMWare it is standard NAT.
We do have DHCP, but this is a static IP address.

First, change the interface from nat to Bridge. Let me know what you got afterwards.

There was a discrepancy in 2003 Service pack 2 that would change the port of listening for Terminal Services and RDP.

https://www.experts-exchange.com/questions/23577994/We-just-recently-started-having-an-issue-with-remote-desktop-we-can-logon-as-local-admin-but-not-domain-admin-the-screen-hangs-and-never-logs-in.html

https://www.experts-exchange.com/questions/23480710/Can-not-use-RDP-to-login-to-server-anymore-get-No-Terminal-Services-Server-Available-error.html

Since you are looking at intermittent communications, It could very well be a DNS issue, just noticed on Terminal services. Do you see other intermittent communications issues, like logging onto a domain, or accessing your mail servers??? If so, concentrate on figuring out if DNS is the problem child and if Terminal services is just a symptom of the problem.

It is not using a standard DNS, as its in its own DMZ. I remote on via ip, and same thing in host machine to get to VMS.

I tried changing the network interface to Bridged but this meant I couldn't login.

What version of RDP client is being used, 6.1?

http://support.microsoft.com/kb/951616

Not using your Top Level Domain Controller for DNS may be the problem. The TDC DNS service will be the only place that holds your SRV records. SRV records are SeRVice records that point the way to your Domain Authentication server for authenitcation. Since the computer you are trying to remote into is not going to see these SRV records, you will probably get an access denied error.

The first thing I would do is make sure I can run a NSlookup to this computer you are trying to remote into. That will verify that DNS is able to reach this computer that is within your DMZ.

If you can get a DNS query resolved to this server, you may have to set up LOCAL credentials for remoting into it. Then, each time you remote into this server, you use the LOCAL credentials to authenticate with instead of domain credentials.

NOTE*** for IT security reasons, use VERY strong Encrypted passwords for any kind of remote access on a DMZ computer.

It seems that if we log onto the server directly, and "Repair" the connection every morning it starts to work after that.

Any ideas?

Have you looked into what port TS is on. Once again SP2 was problematic on what port Terminal services were looking on. This is actually a very common error:

https://www.experts-exchange.com/questions/23480710/Can-not-use-RDP-to-login-to-server-anymore-get-No-Terminal-Services-Server-Available-error.html