Chapter 23. Integrating MS Windows networks with Samba

Date: Wed, 16 Jul 2003 05:34:56 +0000 Subject: trying to get HEAD building again. If you want the code prior to this merge, checkout HEAD_PRE_3_0_0_BETA_3_MERGE (This used to be commit adb98e7b7cd0f025b52c570e4034eebf4047b1ad) --- docs/htmldocs/integrate-ms-networks.html | 159 +++++++++++++++++++++---------- 1 file changed, 111 insertions(+), 48 deletions(-) (limited to 'docs/htmldocs/integrate-ms-networks.html') diff --git a/docs/htmldocs/integrate-ms-networks.html b/docs/htmldocs/integrate-ms-networks.html index 70f446e09d..083aeed9f3 100644 --- a/docs/htmldocs/integrate-ms-networks.html +++ b/docs/htmldocs/integrate-ms-networks.html @@ -1,5 +1,4 @@ - -Chapter 23. Integrating MS Windows networks with Samba

Chapter 23. Integrating MS Windows networks with Samba
Prev	Part III. Advanced Configuration	Next

Chapter 23. Integrating MS Windows networks with Samba

John H. Terpstra

Samba Team

<jht@samba.org>

(Jan 01 2001)

Table of Contents

Name Resolution in a pure Unix/Linux world

/etc/hosts
/etc/resolv.conf
/etc/host.conf
/etc/nsswitch.conf

Name resolution as used within MS Windows networking

The NetBIOS Name Cache
The LMHOSTS file
HOSTS file
DNS Lookup
WINS Lookup

+Chapter 26. Integrating MS Windows networks with Samba

Chapter 26. Integrating MS Windows networks with Samba
Prev	Part III. Advanced Configuration	Next

Chapter 26. Integrating MS Windows networks with Samba

John H. Terpstra

Samba Team

<jht@samba.org>

(Jan 01 2001)

Table of Contents

Features and Benefits

Background Information

Name Resolution in a pure Unix/Linux world

/etc/hosts
/etc/resolv.conf
/etc/host.conf
/etc/nsswitch.conf

Name resolution as used within MS Windows networking

The NetBIOS Name Cache
The LMHOSTS file
HOSTS file
DNS Lookup
WINS Lookup

Common Errors

My Boomerang Won't Come Back
Very Slow Network Connections
Samba server name change problem

This section deals with NetBIOS over TCP/IP name to IP address resolution. If your MS Windows clients are NOT configured to use NetBIOS over TCP/IP then this section does not apply to your installation. If your installation involves use of @@ -10,7 +9,15 @@ NetBIOS over TCP/IP then this section may help you to resolve networking problem to NOT run NetBEUI at all. Note also that there is NO such thing as NetBEUI over TCP/IP - the existence of such a protocol is a complete and utter mis-apprehension. -

Features and Benefits

+Many MS Windows network administrators have never been exposed to basic TCP/IP +networking as it is implemented in a Unix/Linux operating system. Likewise, many Unix and +Linux administrators have not been exposed to the intricacies of MS Windows TCP/IP based +networking (and may have no desire to be either). +

+This chapter gives a short introduction to the basics of how a name can be resolved to +it's IP address for each operating system environment. +

Background Information

Since the introduction of MS Windows 2000 it is possible to run MS Windows networking without the use of NetBIOS over TCP/IP. NetBIOS over TCP/IP uses UDP port 137 for NetBIOS name resolution and uses TCP port 139 for NetBIOS session services. When NetBIOS over @@ -26,16 +33,16 @@ disable NetBIOS over TCP/IP today use MS Active Directory Service (ADS). ADS req Dynamic DNS with Service Resource Records (SRV RR) and with Incremental Zone Transfers (IXFR). Use of DHCP with ADS is recommended as a further means of maintaining central control over client workstation network configuration. -

Name Resolution in a pure Unix/Linux world

The key configuration files covered in this section are: -

/etc/hosts
/etc/resolv.conf
/etc/host.conf
/etc/nsswitch.conf

`/etc/hosts`

/etc/hosts
/etc/resolv.conf
/etc/host.conf
/etc/nsswitch.conf

`/etc/hosts`

Contains a static list of IP Addresses and names. eg: -

+
 	127.0.0.1	localhost localhost.localdomain
 	192.168.1.1	bigbox.caldera.com	bigbox	alias4box
 

-The purpose of /etc/hosts is to provide a 
+The purpose of /etc/hosts is to provide a 
 name resolution mechanism so that uses do not need to remember 
 IP addresses.
 

@@ -43,16 +50,16 @@ Network packets that are sent over the physical network transport
 layer communicate not via IP addresses but rather using the Media 
 Access Control address, or MAC address. IP Addresses are currently 
 32 bits in length and are typically presented as four (4) decimal 
-numbers that are separated by a dot (or period). eg: 168.192.1.1
+numbers that are separated by a dot (or period). eg: 168.192.1.1.
 

 MAC Addresses use 48 bits (or 6 bytes) and are typically represented 
 as two digit hexadecimal numbers separated by colons. eg: 
 40:8e:0a:12:34:56
 

-Every network interfrace must have an MAC address. Associated with 
+Every network interface must have an MAC address. Associated with 
 a MAC address there may be one or more IP addresses. There is NO 
 relationship between an IP address and a MAC address, all such assignments 
-are arbitary or discretionary in nature. At the most basic level all 
+are arbitrary or discretionary in nature. At the most basic level all 
 network communications takes place using MAC addressing. Since MAC 
 addresses must be globally unique, and generally remains fixed for 
 any particular interface, the assignment of an IP address makes sense 
@@ -64,7 +71,7 @@ When a user or a process wants to communicate with another machine
 the protocol implementation ensures that the "machine name" or "host 
 name" is resolved to an IP address in a manner that is controlled 
 by the TCP/IP configuration control files. The file 
-/etc/hosts is one such file.
+/etc/hosts is one such file.
 

 When the IP address of the destination interface has been 
 determined a protocol called ARP/RARP is used to identify 
@@ -78,14 +85,14 @@ ff:ff:ff:ff:ff:ff. The reply packet from an ARP request will
 contain the MAC address and the primary IP address for each 
 interface.
 

-The /etc/hosts file is foundational to all 
-Unix/Linux TCP/IP installations and as a minumum will contain 
+The /etc/hosts file is foundational to all 
+Unix/Linux TCP/IP installations and as a minimum will contain 
 the localhost and local network interface IP addresses and the 
 primary names by which they are known within the local machine. 
 This file helps to prime the pump so that a basic level of name 
 resolution can exist before any other method of name resolution 
 becomes available.
-

`/etc/resolv.conf`

This file tells the name resolution libraries:

The name of the domain to which the machine belongs @@ -95,21 +102,21 @@ This file tells the name resolution libraries:
The name or IP address of available Domain Name Servers that may be asked to perform name to address translation lookups -

`/etc/host.conf`

-/etc/host.conf is the primary means by +

`/etc/host.conf`

+/etc/host.conf is the primary means by which the setting in /etc/resolv.conf may be affected. It is a critical configuration file. This file controls the order by -which name resolution may procede. The typical structure is: -

+which name resolution may proceed. The typical structure is: +

 	order hosts,bind
 	multi on

then both addresses should be returned. Please refer to the man page for host.conf for further details. -

`/etc/nsswitch.conf`

This file controls the actual name resolution targets. The file typically has resolver object specifications as follows: -

+
 	# /etc/nsswitch.conf
 	#
 	# Name Service Switch configuration file.
@@ -123,7 +130,7 @@ file typically has resolver object specifications as follows:
 
 	hosts:		files nis dns
 	# Alternative entries for host name resolution are:
-	# hosts:	files dns nis nis+ hesoid db compat ldap wins
+	# hosts:	files dns nis nis+ hesiod db compat ldap wins
 	networks:	nis files dns
 
 	ethers:		nis files
@@ -142,15 +149,15 @@ Starting with version 2.2.0 samba has Linux support for extensions to
 the name service switch infrastructure so that linux clients will 
 be able to obtain resolution of MS Windows NetBIOS names to IP 
 Addresses. To gain this functionality Samba needs to be compiled 
-with appropriate arguments to the make command (ie: make 
-nsswitch/libnss_wins.so). The resulting library should 
-then be installed in the /lib directory and 
+with appropriate arguments to the make command (ie: make 
+nsswitch/libnss_wins.so). The resulting library should 
+then be installed in the /lib directory and 
 the "wins" parameter needs to be added to the "hosts:" line in 
-the /etc/nsswitch.conf file. At this point it 
+the /etc/nsswitch.conf file. At this point it 
 will be possible to ping any MS Windows machine by it's NetBIOS 
 machine name, so long as that machine is within the workgroup to 
 which both the samba machine and the MS Windows machine belong.
-

Name resolution as used within MS Windows networking

MS Windows networking is predicated about the name each machine is given. This name is known variously (and inconsistently) as the "computer name", "machine name", "networking name", "netbios name", @@ -165,7 +172,7 @@ name is therefore registered for each service type that is provided by the client/server.

The following are typical NetBIOS name/service type registrations: -

+
 	Unique NetBIOS Names:
 		MACHINENAME<00>	= Server Service is running on MACHINENAME
 		MACHINENAME<03> = Generic Machine Name (NetBIOS name)
@@ -184,7 +191,7 @@ installations where traditionally the system administrator will
 determine in the /etc/hosts or in the DNS database what names 
 are associated with each IP address.
 

-One further point of clarification should be noted, the /etc/hosts 
+One further point of clarification should be noted, the /etc/hosts 
 file and the DNS records do not provide the NetBIOS name type information 
 that MS Windows clients depend on to locate the type of service that may 
 be needed. An example of this is what happens when an MS Windows client 
@@ -221,7 +228,7 @@ NBT or NetBT, the NetBIOS over TCP/IP.
 MS Windows machines use a complex array of name resolution mechanisms. 
 Since we are primarily concerned with TCP/IP this demonstration is 
 limited to this area.
-
The NetBIOS Name Cache

+
The NetBIOS Name Cache

 All MS Windows machines employ an in memory buffer in which is 
 stored the NetBIOS names and IP addresses for all external 
 machines that that machine has communicated with over the 
@@ -238,16 +245,16 @@ frustrating for users - but it is a characteristic of the protocol.
 

 The MS Windows utility that allows examination of the NetBIOS 
 name cache is called "nbtstat". The Samba equivalent of this 
-is called "nmblookup".
-
The LMHOSTS file

+is called nmblookup.
+
The LMHOSTS file

 This file is usually located in MS Windows NT 4.0 or 
-2000 in C:\WINNT\SYSTEM32\DRIVERS\ETC and contains 
+2000 in C:\WINNT\SYSTEM32\DRIVERS\ETC and contains 
 the IP Address and the machine name in matched pairs. The 
-LMHOSTS file performs NetBIOS name 
+LMHOSTS file performs NetBIOS name 
 to IP address mapping.
 

 It typically looks like:
-
+
 	# Copyright (c) 1998 Microsoft Corp.
 	#
 	# This is a sample LMHOSTS file used by the Microsoft Wins Client (NetBIOS
@@ -256,7 +263,7 @@ It typically looks like:
 	# This file contains the mappings of IP addresses to NT computernames
 	# (NetBIOS) names.  Each entry should be kept on an individual line.
 	# The IP address should be placed in the first column followed by the
-	# corresponding computername. The address and the comptername
+	# corresponding computername. The address and the computername
 	# should be separated by at least one space or tab. The "#" character
 	# is generally used to denote the start of a comment (see the exceptions
 	# below).
@@ -288,7 +295,7 @@ It typically looks like:
 	# centralized lmhosts file to be maintained on a server.
 	# It is ALWAYS necessary to provide a mapping for the IP address of the
 	# server prior to the #INCLUDE. This mapping must use the #PRE directive.
-	# In addtion the share "public" in the example below must be in the
+	# In addition the share "public" in the example below must be in the
 	# LanManServer list of "NullSessionShares" in order for client machines to
 	# be able to read the lmhosts file successfully. This key is under
 	# \machine\system\currentcontrolset\services\lanmanserver\parameters\nullsessionshares
@@ -324,14 +331,14 @@ It typically looks like:
 	# so keeping the number of comments to a minimum will improve performance.
 	# Therefore it is not advisable to simply add lmhosts file entries onto the
 	# end of this file.
-
HOSTS file

+

HOSTS file

This file is usually located in MS Windows NT 4.0 or 2000 in -C:\WINNT\SYSTEM32\DRIVERS\ETC and contains +C:\WINNT\SYSTEM32\DRIVERS\ETC and contains the IP Address and the IP hostname in matched pairs. It can be used by the name resolution infrastructure in MS Windows, depending on how the TCP/IP environment is configured. This file is in -every way the equivalent of the Unix/Linux /etc/hosts file. -

DNS Lookup

+every way the equivalent of the Unix/Linux /etc/hosts file. +

DNS Lookup

This capability is configured in the TCP/IP setup area in the network configuration facility. If enabled an elaborate name resolution sequence is followed the precise nature of which is dependant on what the NetBIOS @@ -342,23 +349,79 @@ cache. If that fails then DNS, HOSTS and LMHOSTS are checked. If set to Node Type 8, then a NetBIOS Unicast (over UDP Unicast) is sent to the WINS Server to obtain a lookup before DNS, HOSTS, LMHOSTS, or broadcast lookup is used. -

WINS Lookup

-A WINS (Windows Internet Name Server) service is the equivaent of the +

WINS Lookup

+A WINS (Windows Internet Name Server) service is the equivalent of the rfc1001/1002 specified NBNS (NetBIOS Name Server). A WINS server stores the names and IP addresses that are registered by a Windows client if the TCP/IP setup has been given at least one WINS Server IP Address.

To configure Samba to be a WINS server the following parameter needs -to be added to the smb.conf file: -

+to be added to the smb.conf file: +

 	wins support = Yes

To configure Samba to use a WINS server the following parameters are -needed in the smb.conf file: -

+needed in the smb.conf file: +

 	wins support = No
 	wins server = xxx.xxx.xxx.xxx

-where xxx.xxx.xxx.xxx is the IP address +where xxx.xxx.xxx.xxx is the IP address of the WINS server. -

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Common Errors

+TCP/IP network configuration problems find every network administrator sooner or later. +The cause can be anything from keyboard mishaps, forgetfulness, simple mistakes, and +carelessness. Of course, no one is every deliberately careless! +

My Boomerang Won't Come Back

+ Well, the real complaint said, "I can ping my samba server from Windows, but I can + not ping my Windows machine from the samba server." +

+ The Windows machine was at IP Address 192.168.1.2 with netmask 255.255.255.0, the + Samba server (Linux) was at IP Address 192.168.1.130 with netmask 255.255.255.128. + The machines were on a local network with no external connections. +

+ Due to inconsistent netmasks, the Windows machine was on network 192.168.1.0/24, while + the Samba server was on network 192.168.1.128/25 - logically a different network. +

Very Slow Network Connections

+ A common causes of slow network response includes: +

Client is configured to use DNS and DNS server is down
Client is configured to use remote DNS server, but remote connection is down
Client is configured to use a WINS server, but there is no WINS server
Client is NOT configured to use a WINS server, but there is a WINS server
Firewall is filtering our DNS or WINS traffic

Samba server name change problem

+ The name of the samba server was changed, samba was restarted, samba server can not be + pinged by new name from MS Windows NT4 Workstation, but it does still respond to ping using + the old name. Why? +

+ From this description three (3) things are rather obvious: +

WINS is NOT in use, only broadcast based name resolution is used
The samba server was renamed and restarted within the last 10-15 minutes
The old samba server name is still in the NetBIOS name cache on the MS Windows NT4 Workstation

+ To find what names are present in the NetBIOS name cache on the MS Windows NT4 machine, + open a cmd shell, then: +

+	C:\temp\>nbtstat -n
+
+	              NetBIOS Local Name Table
+
+	   Name                 Type          Status
+	------------------------------------------------
+	SLACK            <03>  UNIQUE      Registered
+	ADMINISTRATOR    <03>  UNIQUE      Registered
+	SLACK            <00>  UNIQUE      Registered
+	SARDON           <00>  GROUP       Registered
+	SLACK            <20>  UNIQUE      Registered
+	SLACK            <1F>  UNIQUE      Registered
+
+
+	C:\Temp\>nbtstat -c
+
+	             NetBIOS Remote Cache Name Table
+
+	   Name                 Type       Host Address     Life [sec]
+	--------------------------------------------------------------
+	FRODO            <20>  UNIQUE      192.168.1.1          240
+
+	C:\Temp\>
+

+ In the above example, FRODO is the Samba server and SLACK is the MS Windows NT4 Workstation. + The first listing shows the contents of the Local Name Table (ie: Identity information on + the MS Windows workstation), the second shows the NetBIOS name in the NetBIOS name cache. + The name cache contains the remote machines known to this workstation. +

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