Slow login times when mapping a drive to a server that is down

(Last modified: 06Oct2003)

This document (10076045) is provided subject to the disclaimer at the end of this document.

fact

Novell Client 4.83 for Windows NT/2000/XP

Novell Client 4.83 SP1 for Windows NT/2000/XP

Microsoft Windows 2000 Professional

symptom

Slow login times when mapping a drive to a server that is down

The clients and servers are dual stack (IP and IPX bound)

If the clients are IP only only, login times are faster.

The login times will vary, depending on if Bad Address Cache is enabled or disabled

fix

BACKGROUND AND HISTORY:

Some prior versions of NWFS.SYS had a feature called "Bad Address Cache" enabled by default.  What the bad address cache does is if the client tries to connect to a server and that server is down, the client will try to connect to that server's address and fail.  That address is cached for five minutes and marked as bad.  If a request comes into NWFS.SYS to connect to that bad address while that address is in the bad address cache, the connect attempt will fail immediately.  The bad address cache code was added to NWFS.SYS in late 2001 and was enabled by default.  At the end of January 2002, the bad address cache code was still included in NWFS.SYS, but was disabled by default.  The first implementation of bad address cache was to cache bad IP addresses only.  Bad IPX addresses were not cached.  With NWFS.SYS dated 16OCT2002 or later, bad IP and IPX addresses are both cached and the bad address cache is enabled by default.  What you will see if a server is down with multiple drive mappings to that server is the first drive mapping takes a long time (30 - 60 seconds) to fail, but subsequent drive mappings to that server will fail rapidly and the execution of the login script will continue normally.

Bad Address Cache can cause problems in a network environment, specifically where a server does not respond to the client due to networking difficulties or server problems.  If you are experiencing difficulties with drive mappings failing and such, you can disable bad address cache by adding the following DWORD to your workstation's registry:

HKLM\SYSTEM\CurrentControlSet\Services\NetwareWorkstation\Parameters
DWORD:  BadAddressCacheTimeout
Value: 0     (NOTE:  The value is in seconds.  If you want BadAddressCacheTimeout to be 3 minutes, you would put 180 decimal as the value.)

In some versions of NWFS.SYS, bad address cache is disabled by default.  If you want to enable it, add the above DWORD and then add a value in seconds that you want the cache to run for.  If you suspect that the bad address cache is causing you problems, you can flush the cache by doing an IPCONFIG /RELEASE and then IPCONFIG /RENEW.

Fixed in the Novell Client 4.83 SP2 for Windows NT/2000/XP.

The Novell Client 4.83 SP2 for Windows NT/2000/XP is available from the Novell Support site as NC483SP2.EXE (http://support.novell.com/cgi-bin/search/searchtid.cgi?/2965465.htm)

Fixed in NWFS.SYS dated 16OCT2002 or later and NWSAP.SYS dated 29SEP2002 or later.

document

Document Title: Slow login times when mapping a drive to a server that is down
Document ID: 10076045
Solution ID: NOVL83349
Creation Date: 25Oct2002
Modified Date: 06Oct2003
Novell Product Class:NetWare

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