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Q193834: Behavior of Unreachable Demand Dial Interfaces in RRAS

Article: Q193834
Product(s): Microsoft Windows NT
Version(s): 2000,4.0
Operating System(s): 
Keyword(s): kbnetwork
Last Modified: 10-AUG-2001

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The information in this article applies to:

- Microsoft Routing and Remote Access Service Update for Windows NT Server version 4.0 
- Microsoft Windows NT Server version 4.0 
- Microsoft Windows 2000 Advanced Server 
- Microsoft Windows 2000 Server 
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IMPORTANT: This article contains information about editing the registry.
Before you edit the registry, make sure you understand how to restore it if
a problem occurs. For information about how to do this, view the "Restoring
the Registry" Help topic in Regedit.exe or the "Restoring a Registry Key"
Help topic in Regedt32.exe.

SUMMARY
=======

This article is intended to describe the characteristics of the Routing and
Remote Access Service (RRAS) when a Dial on Demand (DOD) interface attempts to
dial a number that is not available.

MORE INFORMATION
================

When a DOD interface in RRAS attempts to dial a number, the status field will
have a value of "Connecting." The static route that is used to activate the DOD
is viewable by using the KERNROUT PRINT command.

If the number that is dialed is not available, the DOD interface will be marked
"Unreachable" only after it has failed all redial attempts. It will then stay
unreachable for a default period of 10 minutes. The static route disappears from
the routing table when the interface status is marked "Unreachable."

After the wait interval, the status of the DOD interface will change to
"Disconnected," at which point the DOD interface is available for use. When the
status changes to "Disconnected," the static route in KERNROUT will reappear.

If the DOD interface fails to connect again after this wait interval, it will
then be marked "Unreachable" for a period of 20 minutes and, again, the static
route will disappear from KERNROUT. Then, when the wait period is over, the
status goes back to "Disconnected."

This cycle continues in 10 minute intervals until 6 hours has been reached. The
default maximum wait time remains at 6 hours until one of the following occurs:

- A successful connection has been established [through either the wait
  interval described here or manual dialing].

  -or-

- The router has been stopped and restarted.

These default minimum and maximum times can be changed through the registry.

WARNING: Using Registry Editor incorrectly can cause serious problems that may
require you to reinstall your operating system. Microsoft cannot guarantee that
problems resulting from the incorrect use of Registry Editor can be solved. Use
Registry Editor at your own risk.

For information about how to edit the registry, view the "Changing Keys And
Values" Help topic in Registry Editor (Regedit.exe) or the "Add and Delete
Information in the Registry" and "Edit Registry Data" Help topics in
Regedt32.exe. Note that you should back up the registry before you edit it. If
you are running Windows NT, you should also update your Emergency Repair Disk
(ERD).

The 10-minute wait time is a default value that can be changed by adding the
registry entry shown below:

HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Router\Interfaces
\<interface name>\MinUnreachabilityInterval

REG_DWORD with a value in seconds

NOTE: The above registry key is one path; it has been wrapped for readability.

The MinUnreachabilityInterval is the smallest amount of time that the interface
will stay "Unreachable" AND also defines what the wait interval is incremented
by in next attempts.

The maximum wait time is a default value that can be changed by adding the
registry entry shown below:

HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Router\Interfaces
\<interface name>\MaxUnreachabilityInterval

REG_DWORD with a value in seconds

NOTE: The above registry key is one path; it has been wrapped for readability.

The MaxUnreachabilityInterval is the highest wait time the DOD interface will
stay "Unreachable" and RRAS will not increment above this wait time.


Additional query words: ntrouter dial-on-demand static routes lost

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Keywords          : kbnetwork 
Technology        : kbWinNTsearch kbWinNT400search kbwin2000AdvServ kbwin2000AdvServSearch kbwin2000Serv kbWinNTSsearch kbWinNTS400search kbWinNTS400 kbwin2000ServSearch kbwin2000Search kbAudDeveloper kbWinAdvServSearch kbRRASNTSearch kbRRASNT400
Version           : :2000,4.0
Issue type        : kbinfo

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