TCPRelay User guide

Version 1.7


User guide

Case Study

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Put TCPRelay.exe where you want, for example in the WINNT directory.
Type in "TCPRelay.exe -install" and this is it, installation complete.
To remove TCPRelay type in "TCPRelay.exe -remove".
This program does not require special DLL.

If you do an upgrade from a previous version, stop the service, close Event Viewer, replace TCPRelay.exe with the new version and start the service.

We chose this minimalist installation scheme because we are sure you don't like to start heavy blind installation program on your production  park. You certainly have in mind "I hope it will not upgrade a DLL that is incompatible with existing programs !"

TCPRelay is a Windows NT 3.51/4.0/2000 service that works on Server and Workstation.
Starting and stopping
Service name is "TCP Relay". Start it in the service manager program.
Service short name is tcprelay, use it with net start and stop command.
net start tcprelay
net stop tcprelay
All parameters are in the registry at HKEY_LOCAL_MACHINE\Software\XTWare\TCPRelay
See a sample here.

TraceLevel (dword)
This parameters tell the trace level. 0 mean minimal (start, stop and warnings), 2 mean full (client and server connection).

You can create as meany profile as you want. To create a profile add a new key from TCPRelay. For example


Destination (string) mandatory

You specify the server to connect to, the port and serveur IP address to use. The syntaxe is:


IP is the destination address and can be in numerical or DNS format. The DNS internal cache reload if a connection fail.

Port can be in database or numerical format.

IP2 is local interface address to bind to. This value is facultative. Useful on multihome computer only.

For exemple if computer's address is then and are equivalent.

To use interface ( as gateway type in or

Local (string) facultative

This key tell the local address and port to use. If you have several IP address on this machine you can tell on witch to listen to.

The syntax is [IP]:port

If this key doesn't existe then all addresses are used, and the port is the same as the Destination key.

Denied (string) facultative

You can list all denied addresses. Numerical format only. Separate them with a semi colon. Stars means any value, but alway use the a.b.c.d format. (see example)

Authorized (string) facultative

You can list all authorized addresses. Same format as Denied.



Version history
  • Version 1.3
    • Initial version
  • Version 1.4 (11/20/99)
    • New event log messages to help you find out why it doesn't work.
    • DNS caching. The cache is reload if a connection fail.
    • Autorized registry key renamed to Authorized.
  • Version 1.5 (04/27/00)
    • Remove registration process
    • Clearer messages during installation
    • More error messages
  • Version 1.6 (07/01/00)
    • Bug correction on some deconnection problems
  • Version 1.7 (11/11/00)
    • Add interface choice for destination