Chapter 34. Analysing and solving samba problems

Chapter 34. Analysing and solving samba problems
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Gerald (Jerry) Carter

Samba Team

<jerry@samba.org>

Jelmer R. Vernooij

The Samba Team

<jelmer@samba.org>

David Bannon

Samba Team

<dbannon@samba.org>

8 Apr 2003

Table of Contents

Diagnostics tools
Installing 'Network Monitor' on an NT Workstation or a Windows 9x box
Useful URLs
Getting help from the mailing lists
How to get off the mailing lists

-There are many sources of information available in the form -of mailing lists, RFC's and documentation. The docs that come -with the samba distribution contain very good explanations of -general SMB topics such as browsing.

Diagnostics tools

-One of the best diagnostic tools for debugging problems is Samba itself. -You can use the -d option for both smbd and nmbd to specify what -debug level at which to run. See the man pages on smbd, nmbd and -smb.conf for more information on debugging options. The debug -level can range from 1 (the default) to 10 (100 for debugging passwords). -

-Another helpful method of debugging is to compile samba using the -gcc -g flag. This will include debug -information in the binaries and allow you to attach gdb to the -running smbd / nmbd process. In order to attach gdb to an smbd -process for an NT workstation, first get the workstation to make the -connection. Pressing ctrl-alt-delete and going down to the domain box -is sufficient (at least, on the first time you join the domain) to -generate a 'LsaEnumTrustedDomains'. Thereafter, the workstation -maintains an open connection, and therefore there will be an smbd -process running (assuming that you haven't set a really short smbd -idle timeout) So, in between pressing ctrl alt delete, and actually -typing in your password, you can attach gdb and continue. -

-Some useful samba commands worth investigating: -

-	$ testparm | more
-	$ smbclient -L //{netbios name of server}
-

-An SMB enabled version of tcpdump is available from -http://www.tcpdup.org/. -Ethereal, another good packet sniffer for Unix and Win32 -hosts, can be downloaded from http://www.ethereal.com. -

-For tracing things on the Microsoft Windows NT, Network Monitor -(aka. netmon) is available on the Microsoft Developer Network CD's, -the Windows NT Server install CD and the SMS CD's. The version of -netmon that ships with SMS allows for dumping packets between any two -computers (i.e. placing the network interface in promiscuous mode). -The version on the NT Server install CD will only allow monitoring -of network traffic directed to the local NT box and broadcasts on the -local subnet. Be aware that Ethereal can read and write netmon -formatted files. -

Installing 'Network Monitor' on an NT Workstation or a Windows 9x box

-Installing netmon on an NT workstation requires a couple -of steps. The following are for installing Netmon V4.00.349, which comes -with Microsoft Windows NT Server 4.0, on Microsoft Windows NT -Workstation 4.0. The process should be similar for other versions of -Windows NT / Netmon. You will need both the Microsoft Windows -NT Server 4.0 Install CD and the Workstation 4.0 Install CD. -

-Initially you will need to install Network Monitor Tools and Agent -on the NT Server. To do this -

Goto Start - Settings - Control Panel - - Network - Services - Add
Select the Network Monitor Tools and Agent and - click on OK.
Click OK on the Network Control Panel. -
Insert the Windows NT Server 4.0 install CD - when prompted.

-At this point the Netmon files should exist in -%SYSTEMROOT%\System32\netmon\*.*. -Two subdirectories exist as well, parsers\ -which contains the necessary DLL's for parsing the netmon packet -dump, and captures\. -

-In order to install the Netmon tools on an NT Workstation, you will -first need to install the 'Network Monitor Agent' from the Workstation -install CD. -

Goto Start - Settings - Control Panel - - Network - Services - Add
Select the Network Monitor Agent and click - on OK.
Click OK on the Network Control Panel. -
Insert the Windows NT Workstation 4.0 install - CD when prompted.

-Now copy the files from the NT Server in %SYSTEMROOT%\System32\netmon\*.* -to %SYSTEMROOT%\System32\netmon\*.* on the Workstation and set -permissions as you deem appropriate for your site. You will need -administrative rights on the NT box to run netmon. -

-To install Netmon on a Windows 9x box install the network monitor agent -from the Windows 9x CD (\admin\nettools\netmon). There is a readme -file located with the netmon driver files on the CD if you need -information on how to do this. Copy the files from a working -Netmon installation. -

Useful URLs

See how Scott Merrill simulates a BDC behavior at - - http://www.skippy.net/linux/smb-howto.html.
FTP site for older SMB specs: - - ftp://ftp.microsoft.com/developr/drg/CIFS/

Getting help from the mailing lists

-There are a number of Samba related mailing lists. Go to http://samba.org, click on your nearest mirror -and then click on Support and then click on -Samba related mailing lists. -

-For questions relating to Samba TNG go to -http://www.samba-tng.org/ -It has been requested that you don't post questions about Samba-TNG to the -main stream Samba lists.

-If you post a message to one of the lists please observe the following guide lines : -

Always remember that the developers are volunteers, they are -not paid and they never guarantee to produce a particular feature at -a particular time. Any time lines are 'best guess' and nothing more. -
Always mention what version of samba you are using and what -operating system its running under. You should probably list the -relevant sections of your smb.conf file, at least the options -in [global] that affect PDC support.
In addition to the version, if you obtained Samba via -CVS mention the date when you last checked it out.
Try and make your question clear and brief, lots of long, -convoluted questions get deleted before they are completely read ! -Don't post html encoded messages (if you can select colour or font -size its html).
If you run one of those nifty 'I'm on holidays' things when -you are away, make sure its configured to not answer mailing lists. -
Don't cross post. Work out which is the best list to post to -and see what happens, i.e. don't post to both samba-ntdom and samba-technical. -Many people active on the lists subscribe to more -than one list and get annoyed to see the same message two or more times. -Often someone will see a message and thinking it would be better dealt -with on another, will forward it on for you.
You might include partial -log files written at a debug level set to as much as 20. -Please don't send the entire log but enough to give the context of the -error messages.
(Possibly) If you have a complete netmon trace ( from the opening of -the pipe to the error ) you can send the *.CAP file as well.
Please think carefully before attaching a document to an email. -Consider pasting the relevant parts into the body of the message. The samba -mailing lists go to a huge number of people, do they all need a copy of your -smb.conf in their attach directory?

How to get off the mailing lists

To have your name removed from a samba mailing list, go to the -same place you went to to get on it. Go to http://lists.samba.org, -click on your nearest mirror and then click on Support and -then click on Samba related mailing lists. Or perhaps see -here -

-Please don't post messages to the list asking to be removed, you will just -be referred to the above address (unless that process failed in some way...) -

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