Question : Can't RDP to terminal server over VPN. RDP over VPN to desktop PCs and DC works.

We have a very strange problem setting up a VPN network at a site.
The situation is we can RDP to any desktop computer from a remote site across the VPN on the network and even the SBS server but we can not RDP across the VPN into the terminal server. We could not terminal serve into the old terminal server either that was a white box thing that has hardware errors. However, on the local site to the terminal server and domain controller, we can RDP into the terminal server and all other computers.
The error message we get when we try to rdp into the terminal server is: "The client could not connect to the remote computer". We can Ping the terminal server from the remote site, access UNC shares on the terminal server and join PCs to the domain.

We've tried:
Remote desktop is enabled

Windows 2003 terminal server is activated and licences installed

All CALS have been installed, all software is licenced and legitamate

Analysing the packets. Traffic reaches the terminal server but then dissappears without error. Used programs ISA Server 2004 Standard, Wire Shark and Windows firewall log.

Tried removing the terminal server from the domain, aplpying relaxed security policy, disabling windows firewall client service and uninstalling the ISA firewall client.

Changing subnets from 10.0.15.x, 10.0.16.x to 192.168.20.x, 192.168.11.x.

Updating network card drivers to the latest off the HP web site.

disabling RSS on TCP/IP protocol.

Add IP helper command to Cisco router to allow broadcasting across the VPN.

Changing MTU size and window segment size on the VPN.

The equiptment we are using is:
DL380 G5 server for both a terminal server and Domain controller, I.e. 2 servers
3 Cisco 857 Routers
Netgear and CISCO unmanaged switch.
the Software we are using is:
Windows 2003 server R2 for terminal server
Windows 2003 SBS server R2 for domain controller.

Current IP setup:
Remtoe Site
PC: 192.168.11.210
Router: 192.168.11.254
DNS: 192.168.20.210

Local terminal server Site:
Terminal Server: 192.168.20.211
SBS Server: 192.168.20.210
Other PC: 192.168.20.103
VPN Router: 192.168.20.254
DNS: 192.168.20.210
Internet Router: 192.168.10.254

SBS Server has two network cards:
first
IP: 192.168.20.210
subnet 255.255.255.0
DNS 192.168.20.210
gateway: 192.168.20.254

2nd
IP: 192.168.20.210
subnet 255.255.255.0
DNS: 192.168.20.210
gateway: 192.168.20.254

Will try later:
Different routers
Differnt ISP
Different network card in TS although TS currently has 2 network cards and neither works.

Please offer suggestions as I doubt changing the above 3 things will work and will take a long time to test. We setup these types of networks all the time and I really doubt the CISCO config will be the problem. The servers have the latest firmware packs install (version 7.7). I fyou need any more info please let me know.

Answer : Can't RDP to terminal server over VPN. RDP over VPN to desktop PCs and DC works.

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Computer101
EE Admin