1<?xml version="1.0" encoding="iso-8859-1"?> 2<!DOCTYPE chapter PUBLIC "-//Samba-Team//DTD DocBook V4.2-Based Variant V1.0//EN" "http://www.samba.org/samba/DTD/samba-doc"> 3<chapter id="problems"> 4 5<chapterinfo> 6 &author.jerry; 7 &author.jelmer; 8 &author.dbannon; 9 &author.danshearer; 10 <pubdate>8 Apr 2003</pubdate> 11</chapterinfo> 12 13<title>Analyzing and Solving Samba Problems</title> 14 15<para> 16<indexterm><primary>RFCs</primary></indexterm> 17<indexterm><primary>SMB</primary></indexterm> 18<indexterm><primary>documentation</primary></indexterm> 19There are many sources of information available in the form of mailing lists, RFCs, and documentation. The 20documentation that comes with the Samba distribution contains good explanations of general SMB topics such as 21browsing. 22</para> 23 24<sect1> 25<title>Diagnostics Tools</title> 26 27<para> 28<indexterm><primary>sniffer</primary></indexterm> 29<indexterm><primary>LAN</primary></indexterm> 30<indexterm><primary>analyzes data</primary></indexterm> 31<indexterm><primary>SMB networking</primary></indexterm> 32<indexterm><primary>network analyzer</primary></indexterm> 33With SMB networking, it is often not immediately clear what the cause is of a certain problem. Samba itself 34provides rather useful information, but in some cases you might have to fall back to using a 35<emphasis>sniffer</emphasis>. A sniffer is a program that listens on your LAN, analyzes the data sent on it, 36and displays it on the screen. 37</para> 38 39<sect2> 40<title>Debugging with Samba Itself</title> 41 42<para> 43<indexterm><primary>diagnostic tools</primary></indexterm> 44<indexterm><primary>debugging problems</primary></indexterm> 45<indexterm><primary>smbd</primary></indexterm> 46<indexterm><primary>nmbd</primary></indexterm> 47<indexterm><primary>debugging passwords</primary></indexterm> 48<indexterm><primary>debug level</primary></indexterm> 49<indexterm><primary>log level</primary></indexterm> 50One of the best diagnostic tools for debugging problems is Samba itself. You can use the <option>-d 51option</option> for both &smbd; and &nmbd; to specify the <smbconfoption name="debug level"/> at which to run. 52See the man pages for <command>smbd, nmbd</command>, and &smb.conf; for more information regarding debugging 53options. The debug level (log level) can range from 1 (the default) to 10 (100 for debugging passwords). 54</para> 55 56<para> 57<indexterm><primary>debugging</primary></indexterm> 58<indexterm><primary>gcc</primary></indexterm> 59<indexterm><primary>gdb</primary></indexterm> 60<indexterm><primary>smbd</primary></indexterm> 61<indexterm><primary>nmbd</primary></indexterm> 62<indexterm><primary>LsaEnumTrustedDomains</primary></indexterm> 63<indexterm><primary>attach gdb</primary></indexterm> 64Another helpful method of debugging is to compile Samba using the <command>gcc -g </command> flag. This will 65include debug information in the binaries and allow you to attach <command>gdb</command> to the running 66<command>smbd/nmbd</command> process. To attach <command>gdb</command> to an <command>smbd</command> process 67for an NT workstation, first get the workstation to make the connection. Pressing ctrl-alt-delete and going 68down to the domain box is sufficient (at least, the first time you join the domain) to generate a 69<parameter>LsaEnumTrustedDomains</parameter>. Thereafter, the workstation maintains an open connection and 70there will be an smbd process running (assuming that you haven't set a really short smbd idle timeout). So, in 71between pressing <command>ctrl-alt-delete</command> and actually typing in your password, you can attach 72<command>gdb</command> and continue. 73</para> 74 75<para> 76Some useful Samba commands worth investigating are: 77<indexterm><primary>testparm</primary></indexterm> 78<indexterm><primary>smbclient</primary></indexterm> 79<screen> 80&prompt;<userinput>testparm | more</userinput> 81&prompt;<userinput>smbclient -L //{netbios name of server}</userinput> 82</screen> 83</para> 84 85</sect2> 86 87<sect2> 88 <title>Tcpdump</title> 89 90<para> 91<indexterm><primary>tcpdump</primary></indexterm> 92<indexterm><primary>tethereal</primary></indexterm> 93<indexterm><primary>ethereal</primary></indexterm> 94<ulink url="http://www.tcpdump.org/">Tcpdump</ulink> was the first 95UNIX sniffer with SMB support. It is a command-line utility and 96now, its SMB support is somewhat lagging that of <command>ethereal</command> 97and <command>tethereal</command>. 98</para> 99 100</sect2> 101 102<sect2> 103 <title>Ethereal</title> 104 105<para> 106<indexterm><primary>ethereal</primary></indexterm> 107<ulink url="http://www.ethereal.com/">Ethereal</ulink> is a graphical sniffer, available for both UNIX (Gtk) 108and Windows. Ethereal's SMB support is quite good. For details on the use of <command>ethereal</command>, read 109the well-written Ethereal User Guide. 110</para> 111 112<figure id="ethereal1"><title>Starting a Capture.</title><imagefile>ethereal1</imagefile></figure> 113 114<para> 115<indexterm><primary>ports</primary></indexterm> 116Listen for data on ports 137, 138, 139, and 445. For example, use the filter <userinput>port 137, port 138, 117port 139, or port 445</userinput> as seen in <link linkend="ethereal1">Starting a Capture</link> snapshot. 118</para> 119 120<para> 121A console version of ethereal is available as well and is called <command>tethereal</command>. 122</para> 123 124<figure id="ethereal2"><title>Main Ethereal Data Window.</title><imagefile>ethereal2</imagefile></figure> 125 126</sect2> 127 128<sect2> 129<title>The Windows Network Monitor</title> 130 131<para> 132<indexterm><primary>Network Monitor</primary></indexterm> 133<indexterm><primary>Netmon</primary></indexterm> 134<indexterm><primary>Microsoft Developer Network CDs</primary></indexterm> 135<indexterm><primary>SMS</primary></indexterm> 136<indexterm><primary>promiscuous mode</primary></indexterm> 137<indexterm><primary>ethereal</primary></indexterm> 138For tracing things on Microsoft Windows NT, Network Monitor (aka Netmon) is available on Microsoft Developer 139Network CDs, the Windows NT Server install CD, and the SMS CDs. The version of Netmon that ships with SMS 140allows for dumping packets between any two computers (i.e., placing the network interface in promiscuous 141mode). The version on the NT Server install CD will only allow monitoring of network traffic directed to the 142local NT box and broadcasts on the local subnet. Be aware that Ethereal can read and write Netmon formatted 143files. 144</para> 145 146<sect3> 147<title>Installing Network Monitor on an NT Workstation</title> 148 149<para> 150<indexterm><primary>Netmon.</primary></indexterm> 151Installing Netmon on an NT workstation requires a couple of steps. The following are instructions for 152installing Netmon V4.00.349, which comes with Microsoft Windows NT Server 4.0, on Microsoft Windows NT 153Workstation 4.0. The process should be similar for other versions of Windows NT version of Netmon. You will 154need both the Microsoft Windows NT Server 4.0 Install CD and the Workstation 4.0 Install CD. 155</para> 156 157<para> 158<indexterm><primary>Network Monitor Tools and Agent</primary></indexterm> 159Initially you will need to install <application>Network Monitor Tools and Agent</application> 160on the NT Server to do this: 161</para> 162 163<itemizedlist> 164 <listitem><para>Go to <guibutton>Start</guibutton> -> <guibutton>Settings</guibutton> -> <guibutton>Control Panel</guibutton> -> 165 <guibutton>Network</guibutton> -> <guibutton>Services</guibutton> -> <guibutton>Add</guibutton>.</para></listitem> 166 167 <listitem><para>Select the <guilabel>Network Monitor Tools and Agent</guilabel> and click on <guibutton>OK</guibutton>.</para></listitem> 168 169 <listitem><para>Click on <guibutton>OK</guibutton> on the Network Control Panel.</para></listitem> 170 171 <listitem><para>Insert the Windows NT Server 4.0 install CD when prompted.</para></listitem> 172</itemizedlist> 173 174<para> 175At this point, the Netmon files should exist in <filename>%SYSTEMROOT%\System32\netmon\*.*</filename>. 176Two subdirectories exist as well: <filename>parsers\</filename>, which contains the necessary DLLs 177for parsing the Netmon packet dump, and <filename>captures\</filename>. 178</para> 179 180<para> 181To install the Netmon tools on an NT Workstation, you will first need to install the 182Network Monitor Agent from the Workstation install CD. 183</para> 184 185<itemizedlist> 186 <listitem><para>Go to <guibutton>Start</guibutton> -> <guibutton>Settings</guibutton> -> 187 <guibutton>Control Panel</guibutton> -> <guibutton>Network</guibutton> -> 188 <guibutton>Services</guibutton> -> <guibutton>Add</guibutton>.</para></listitem> 189 190 <listitem><para>Select the <guilabel>Network Monitor Agent</guilabel>, click on 191 <guibutton>OK</guibutton>.</para></listitem> 192 193 <listitem><para>Click on <guibutton>OK</guibutton> in the Network Control Panel. 194 </para></listitem> 195 196 <listitem><para>Insert the Windows NT Workstation 4.0 install CD when prompted.</para></listitem> 197</itemizedlist> 198 199<para> 200Now copy the files from the NT Server in <filename>%SYSTEMROOT%\System32\netmon</filename> 201to <filename>%SYSTEMROOT%\System32\netmon</filename> on the workstation and set permissions 202as you deem appropriate for your site. You will need administrative rights on the NT box to run Netmon. 203</para> 204 205</sect3> 206<sect3> 207<title>Installing Network Monitor on Windows 9x/Me</title> 208<para> 209To install Netmon on Windows 9x/Me, install the Network Monitor Agent 210from the Windows 9x/Me CD (<filename>\admin\nettools\netmon</filename>). 211There is a readme file included with the Netmon driver files on the CD if you need 212information on how to do this. Copy the files from a working Netmon installation. 213</para> 214</sect3> 215</sect2> 216</sect1> 217 218<sect1> 219<title>Useful URLs</title> 220<itemizedlist> 221 222<listitem><para>See how Scott Merrill simulates a BDC behavior at 223 <ulink noescape="1" url="http://www.skippy.net/linux/smb-howto.html"> 224 http://www.skippy.net/linux/smb-howto.html</ulink>. </para></listitem> 225 226<listitem><para>FTP site for older SMB specs, 227 <ulink noescape="1" url="ftp://ftp.microsoft.com/developr/drg/CIFS/"> 228 ftp://ftp.microsoft.com/developr/drg/CIFS/</ulink></para></listitem>. 229 230</itemizedlist> 231 232</sect1> 233 234<sect1> 235<title>Getting Mailing List Help</title> 236 237<para> 238There are a number of Samba-related mailing lists. Go to <ulink 239noescape="1" url="http://samba.org">http://samba.org</ulink>, click on your nearest mirror, 240and then click on <command>Support</command>. Next, click on <command> 241Samba-related mailing lists</command>. 242</para> 243 244<para> 245For questions relating to Samba TNG, go to 246<ulink noescape="1" url="http://www.samba-tng.org/">http://www.samba-tng.org/</ulink>. 247It has been requested that you do not post questions about Samba-TNG to the 248mainstream Samba lists.</para> 249 250<para> 251If you do post a message to one of the lists, please observe the following guidelines: 252</para> 253 254<itemizedlist> 255 256 <listitem><para> 257<indexterm><primary>volunteers</primary></indexterm> 258 Always remember that the developers are volunteers; they are 259 not paid and they never guarantee to produce a particular feature at 260 a particular time. Any timelines are <quote>best guess,</quote> and nothing more. 261 </para></listitem> 262 263 <listitem><para> 264<indexterm><primary>PDC</primary></indexterm> 265 Always mention what version of Samba you are using and what 266 operating system it's running under. You should list the relevant sections of 267 your &smb.conf; file, at least the options in <smbconfsection name="[global]"/> 268 that affect PDC support. 269 </para></listitem> 270 271 <listitem><para>In addition to the version, if you obtained Samba via 272 CVS, mention the date when you last checked it out.</para></listitem> 273 274 <listitem><para> Try to make your questions clear and brief. Lots of long, 275 convoluted questions get deleted before they are completely read! 276 Do not post HTML-encoded messages. Most people on mailing lists simply delete 277 them. 278 </para></listitem> 279 280 <listitem><para> If you run one of those nifty <quote>I'm on holiday</quote> things when 281 you are away, make sure its configured to not answer mailing list traffic. Autoresponses 282 to mailing lists really irritate the thousands of people who end up having to deal 283 with such bad netiquet bahavior. 284 </para></listitem> 285 286 <listitem><para> 287<indexterm><primary>cross post</primary></indexterm> 288 Don't cross post. Work out which is the best list to post to 289 and see what happens. Do not post to both samba-ntdom and samba-technical. 290 Many people active on the lists subscribe to more 291 than one list and get annoyed to see the same message two or more times. 292 Often someone who thinks a message would be better dealt 293 with on another list will forward it on for you.</para></listitem> 294 295 <listitem><para>You might include <emphasis>partial</emphasis> 296 log files written at a log level set to as much as 20. 297 Please do not send the entire log but just enough to give the context of the 298 error messages.</para></listitem> 299 300 <listitem><para>If you have a complete Netmon trace (from the opening of 301 the pipe to the error), you can send the *.CAP file as well.</para></listitem> 302 303 <listitem><para>Please think carefully before attaching a document to an email. 304 Consider pasting the relevant parts into the body of the message. The Samba 305 mailing lists go to a huge number of people. Do they all need a copy of your 306 &smb.conf; in their attach directory?</para></listitem> 307 308</itemizedlist> 309 310</sect1> 311 312<sect1> 313<title>How to Get Off the Mailing Lists</title> 314 315<para>To have your name removed from a Samba mailing list, go to the same 316place where you went to 317subscribe to it, go to <ulink noescape="1" url="http://lists.samba.org/">http://lists.samba.org</ulink>, 318click on your nearest mirror, click on <command>Support</command>, and 319then click on <command>Samba-related mailing lists</command>. 320</para> 321 322<para> 323Please do not post messages to the list asking to be removed. You will only 324be referred to the above address (unless that process failed in some way). 325</para> 326 327</sect1> 328 329</chapter> 330