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Remote Debugging Tools

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Posted: 1 Jun 2004

NOTE: This utility is provided as a courtesy, and is not a Novell supported product. This releases RDBHOST and IMGHOST independent of a NetWare Support Pack. SPs may contain later versions.

RDB, the Remote Debugger, can stay connected to the NetWare console even if the server has crashed or is in the debugger. RDB can upload and download files from the server. RDB consists of RDB.EXE (client) and RDBHOST.NLM (server).

IMGHOST receives NetWare coredumps over the network. Writing a coredump over a network requires that DBNET5 or DBNET6 be loaded. If loaded, the following option appears prior to writing a coredump:

Where should diagnostic core dump be sent?

  1. HDISK -- Hard drive (DOS partition)
  2. NETWORK -- Dump across network to remote host

A sample RDBHOST.CFG is provided. DBNET5.NLM and DBNET6.NLM are contained in and updated by NetWare Support Packs.



  1. Copy RDB.EXE to a DOS/Windows PC that has a TCP/IP connection with network accessibility to the NetWare server(s) to be managed.
  2. Copy RDBHOST.NLM to the SYS:\SYSTEM directory of the server(s) to be managed.
  3. Load RDBHOST.NLM on the server(s).
  4. Create the SYS:\RDB and SYS:\RDB\OUTBOX directories to facilitate file upload/download.


  1. Copy IMGHOST.EXE to the DOS/Windows PC that will be receiving the NetWare coredump.
  1. Copy IMGHOST.NLM to the NetWare server that will be receiving the NetWare coredump.

RDB Client Commands:

(this info is available when connected via RDB by pressing SHIFT-F1):

SHIFT-F1: Display command help
SHIFT-F2: Save currently displayed screen to RDB.LOG on RDB client
SHIFT-F3: Adjust periodic screen logging interval on RDB client
SHIFT-F4: Enable / Disable periodic screen logging to RDB client
SHIFT-F5: Break server into the debugger
SHIFT-F6: Adjust periodic key playback interval on RDB client
SHIFT-F7: Start/Stop keystroke recorder to RDB client
SHIFT-F8: Playback keystroke record from RDB client
SHIFT-F9: Enable periodic playback of keystroke record
SHIFT-F10: Upload file to remote server (upload filess to SYS:\RDB directory)
SHIFT-F11: Download files from remote server (downloads all files in SYS:\RDB\OUTBOX directory)
SHIFT-F12:   Display connected users


  1. SHIFT-F5 will enter the NetWare debugger, i.e. the system halts. Due to some older Gigabit drivers not properly initializing in the debug instance of the driver, the LAN driver may need to be updated for this to work.
  2. SHIFT-F12 will display the identity of the connected user, as configured in that user's RDB.INI, environment variables, or from the command line used to launch RDB.EXE. Press SHIFT-F12 for details on each option.
  3. Neither SYS:\RDB nor SYS:\RDB\OUTBOX exist on a default NetWare system. These directories are used to upload/download files with RDB. Uploading files with SHIFT-F10 will create SYS:\RDB. SYS:\RDB\OUTBOX must be created manually.

Restricting RDB Access to an Appliance:

Access to an appliance via RDB can be limited by firewall (RDB uses UDP port 8880 to communicate), by setting an RDBHOST password, or by configuring SYS:SYSTEM\RDBHOST.CFG.

To set an RDBHOST password, enter the following at the NetWare server prompt after RDBHOST.NLM has been loaded: RDBHOST SET PASSWORD <new password> <old password>. When an RDBHOST password has been set, the password will be required for all future RDB client connections.

***WARNING***: If the RDBHOST password is forgotten, it cannot be recovered. The RDBHOST RESET PASSWORD command can be used to set the password to a value known only to Novell Technical Support. If this command is used, Novell _must_ have telnet or RDB access to that device in order to reset the password. This is a security feature to prevent easy resetting of the RDB password by simply gaining physical console access. If Novell Technical Support cannot remotely connect to the device, the only remaining option is to completely rebuild the server. Upgrades will not change the RDB password.


SYS:SYSTEM\RDBHOST.CFG can be configured to limit access to certain IP addresses, networks, or subnets. Below is a sample configuration of RDBHOST.CFG .

[Accept Addresses],, ; Sample Administrator addresses

[Accept Ranges] ; Sample Administrator networks
10.100.300.15-1.105.300.47 ; Sample IS Staff networks

[Accept Subnets] ; Sample Building 1 ; Sample Building 2
10.300.50.0 ; Sample Building 3

NOTE: If RDBHOST.CFG exists, but it empty, then RDBHOST.NLM will permit RDB client access from any IP address. If RDBHOST.CFG does not exist, RDB client access will be permitted only from Novell networks.

Additional RDB and DBNET Commands:
Additional RDBHOST and DBNET commands may be found by typing RDBHOST or DBHELP at the NetWare command line.

To download the self-extracting file, rdebugtools2.exe, see TID #2968836.

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