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author | John Terpstra <jht@samba.org> | 2003-04-22 06:22:20 +0000 |
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committer | John Terpstra <jht@samba.org> | 2003-04-22 06:22:20 +0000 |
commit | 69321d1fc48795aaff73b64455c0330beb458a02 (patch) | |
tree | f83e16ec8ebbb7af2b0d182b357f8b8724067951 /docs/docbook/projdoc | |
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diff --git a/docs/docbook/projdoc/Browsing-Quickguide.sgml b/docs/docbook/projdoc/Browsing-Quickguide.sgml deleted file mode 100644 index ed5b9a61af..0000000000 --- a/docs/docbook/projdoc/Browsing-Quickguide.sgml +++ /dev/null @@ -1,390 +0,0 @@ -<chapter id="Browsing-Quick"> -<chapterinfo> - &author.jht; - <pubdate>July 5, 1998</pubdate> - <pubdate>Updated: March 15, 2003</pubdate> -</chapterinfo> - -<title>Quick Cross Subnet Browsing / Cross Workgroup Browsing guide</title> - -<para> -This document should be read in conjunction with Browsing and may -be taken as the fast track guide to implementing browsing across subnets -and / or across workgroups (or domains). WINS is the best tool for resolution -of NetBIOS names to IP addesses. WINS is NOT involved in browse list handling -except by way of name to address mapping. -</para> - -<note><para> -MS Windows 2000 and later can be configured to operate with NO NetBIOS -over TCP/IP. Samba-3 and later also supports this mode of operation. -</para></note> - - -<sect1> -<title>Discussion</title> - -<para> -Firstly, all MS Windows networking is based on SMB (Server Message -Block) based messaging. SMB messaging may be implemented using NetBIOS or -without NetBIOS. Samba implements NetBIOS by encapsulating it over TCP/IP. -MS Windows products can do likewise. NetBIOS based networking uses broadcast -messaging to affect browse list management. When running NetBIOS over -TCP/IP this uses UDP based messaging. UDP messages can be broadcast or unicast. -</para> - -<para> -Normally, only unicast UDP messaging can be forwarded by routers. The -<command>remote announce</command> -parameter to smb.conf helps to project browse announcements -to remote network segments via unicast UDP. Similarly, the -<command>remote browse sync</command> parameter of <filename>smb.conf</filename> -implements browse list collation using unicast UDP. -</para> - -<para> -Secondly, in those networks where Samba is the only SMB server technology -wherever possible &nmbd; should be configured on one (1) machine as the WINS -server. This makes it easy to manage the browsing environment. If each network -segment is configured with it's own Samba WINS server, then the only way to -get cross segment browsing to work is by using the -<command>remote announce</command> and the <command>remote browse sync</command> -parameters to your <filename>smb.conf</filename> file. -</para> - -<para> -If only one WINS server is used for an entire multi-segment network then -the use of the <command>remote announce</command> and the -<command>remote browse sync</command> parameters should NOT be necessary. -</para> - -<para> -As of Samba 3 WINS replication is being worked on. The bulk of the code has -been committed, but it still needs maturation. -</para> - -<para> -Right now samba WINS does not support MS-WINS replication. This means that -when setting up Samba as a WINS server there must only be one &nmbd; configured -as a WINS server on the network. Some sites have used multiple Samba WINS -servers for redundancy (one server per subnet) and then used -<command>remote browse sync</command> and <command>remote announce</command> -to affect browse list collation across all -segments. Note that this means clients will only resolve local names, -and must be configured to use DNS to resolve names on other subnets in -order to resolve the IP addresses of the servers they can see on other -subnets. This setup is not recommended, but is mentioned as a practical -consideration (ie: an 'if all else fails' scenario). -</para> - -<para> -Lastly, take note that browse lists are a collection of unreliable broadcast -messages that are repeated at intervals of not more than 15 minutes. This means -that it will take time to establish a browse list and it can take up to 45 -minutes to stabilise, particularly across network segments. -</para> - -</sect1> - -<sect1> -<title>How browsing functions and how to deploy stable and -dependable browsing using Samba</title> - - -<para> -As stated above, MS Windows machines register their NetBIOS names -(i.e.: the machine name for each service type in operation) on start -up. Also, as stated above, the exact method by which this name registration -takes place is determined by whether or not the MS Windows client/server -has been given a WINS server address, whether or not LMHOSTS lookup -is enabled, or if DNS for NetBIOS name resolution is enabled, etc. -</para> - -<para> -In the case where there is no WINS server all name registrations as -well as name lookups are done by UDP broadcast. This isolates name -resolution to the local subnet, unless LMHOSTS is used to list all -names and IP addresses. In such situations Samba provides a means by -which the samba server name may be forcibly injected into the browse -list of a remote MS Windows network (using the -<command>remote announce</command> parameter). -</para> - -<para> -Where a WINS server is used, the MS Windows client will use UDP -unicast to register with the WINS server. Such packets can be routed -and thus WINS allows name resolution to function across routed networks. -</para> - -<para> -During the startup process an election will take place to create a -local master browser if one does not already exist. On each NetBIOS network -one machine will be elected to function as the domain master browser. This -domain browsing has nothing to do with MS security domain control. -Instead, the domain master browser serves the role of contacting each local -master browser (found by asking WINS or from LMHOSTS) and exchanging browse -list contents. This way every master browser will eventually obtain a complete -list of all machines that are on the network. Every 11-15 minutes an election -is held to determine which machine will be the master browser. By the nature of -the election criteria used, the machine with the highest uptime, or the -most senior protocol version, or other criteria, will win the election -as domain master browser. -</para> - -<para> -Clients wishing to browse the network make use of this list, but also depend -on the availability of correct name resolution to the respective IP -address/addresses. -</para> - -<para> -Any configuration that breaks name resolution and/or browsing intrinsics -will annoy users because they will have to put up with protracted -inability to use the network services. -</para> - -<para> -Samba supports a feature that allows forced synchonisation -of browse lists across routed networks using the <command>remote -browse sync</command> parameter in the <filename>smb.conf</filename> file. -This causes Samba to contact the local master browser on a remote network and -to request browse list synchronisation. This effectively bridges -two networks that are separated by routers. The two remote -networks may use either broadcast based name resolution or WINS -based name resolution, but it should be noted that the <command>remote -browse sync</command> parameter provides browse list synchronisation - and -that is distinct from name to address resolution, in other -words, for cross subnet browsing to function correctly it is -essential that a name to address resolution mechanism be provided. -This mechanism could be via DNS, <filename>/etc/hosts</filename>, -and so on. -</para> - -</sect1> - -<sect1> -<title>Use of the <command>Remote Announce</command> parameter</title> -<para> -The <command>remote announce</command> parameter of -<filename>smb.conf</filename> can be used to forcibly ensure -that all the NetBIOS names on a network get announced to a remote network. -The syntax of the <command>remote announce</command> parameter is: -<programlisting> - remote announce = <replaceable>a.b.c.d [e.f.g.h]</replaceable> ... -</programlisting> -_or_ -<programlisting> - remote announce = <replaceable>a.b.c.d/WORKGROUP [e.f.g.h/WORKGROUP]</replaceable> ... -</programlisting> - -where: -<variablelist> -<varlistentry><term><replaceable>a.b.c.d</replaceable> and -<replaceable>e.f.g.h</replaceable></term> -<listitem><para>is either the LMB (Local Master Browser) IP address -or the broadcst address of the remote network. -ie: the LMB is at 192.168.1.10, or the address -could be given as 192.168.1.255 where the netmask -is assumed to be 24 bits (255.255.255.0). -When the remote announcement is made to the broadcast -address of the remote network every host will receive -our announcements. This is noisy and therefore -undesirable but may be necessary if we do NOT know -the IP address of the remote LMB.</para></listitem> -</varlistentry> - -<varlistentry> -<term><replaceable>WORKGROUP</replaceable></term> -<listitem><para>is optional and can be either our own workgroup -or that of the remote network. If you use the -workgroup name of the remote network then our -NetBIOS machine names will end up looking like -they belong to that workgroup, this may cause -name resolution problems and should be avoided. -</para></listitem> -</varlistentry> -</variablelist> -</para> - -</sect1> - -<sect1> -<title>Use of the <command>Remote Browse Sync</command> parameter</title> - -<para> -The <command>remote browse sync</command> parameter of -<filename>smb.conf</filename> is used to announce to -another LMB that it must synchronise it's NetBIOS name list with our -Samba LMB. It works ONLY if the Samba server that has this option is -simultaneously the LMB on it's network segment. -</para> - -<para> -The syntax of the <command>remote browse sync</command> parameter is: - -<programlisting> -remote browse sync = <replaceable>a.b.c.d</replaceable> -</programlisting> - -where <replaceable>a.b.c.d</replaceable> is either the IP address of the remote LMB or else is the network broadcast address of the remote segment. -</para> - -</sect1> - -<sect1> -<title>Use of WINS</title> - -<para> -Use of WINS (either Samba WINS _or_ MS Windows NT Server WINS) is highly -recommended. Every NetBIOS machine registers it's name together with a -name_type value for each of of several types of service it has available. -eg: It registers it's name directly as a unique (the type 0x03) name. -It also registers it's name if it is running the lanmanager compatible -server service (used to make shares and printers available to other users) -by registering the server (the type 0x20) name. -</para> - -<para> -All NetBIOS names are up to 15 characters in length. The name_type variable -is added to the end of the name - thus creating a 16 character name. Any -name that is shorter than 15 characters is padded with spaces to the 15th -character. ie: All NetBIOS names are 16 characters long (including the -name_type information). -</para> - -<para> -WINS can store these 16 character names as they get registered. A client -that wants to log onto the network can ask the WINS server for a list -of all names that have registered the NetLogon service name_type. This saves -broadcast traffic and greatly expedites logon processing. Since broadcast -name resolution can not be used across network segments this type of -information can only be provided via WINS _or_ via statically configured -<filename>lmhosts</filename> files that must reside on all clients in the -absence of WINS. -</para> - -<para> -WINS also serves the purpose of forcing browse list synchronisation by all -LMB's. LMB's must synchronise their browse list with the DMB (domain master -browser) and WINS helps the LMB to identify it's DMB. By definition this -will work only within a single workgroup. Note that the domain master browser -has NOTHING to do with what is referred to as an MS Windows NT Domain. The -later is a reference to a security environment while the DMB refers to the -master controller for browse list information only. -</para> - -<para> -Use of WINS will work correctly only if EVERY client TCP/IP protocol stack -has been configured to use the WINS server/s. Any client that has not been -configured to use the WINS server will continue to use only broadcast based -name registration so that WINS may NEVER get to know about it. In any case, -machines that have not registered with a WINS server will fail name to address -lookup attempts by other clients and will therefore cause workstation access -errors. -</para> - -<para> -To configure Samba as a WINS server just add -<command>wins support = yes</command> to the <filename>smb.conf</filename> -file [globals] section. -</para> - -<para> -To configure Samba to register with a WINS server just add -"wins server = a.b.c.d" to your smb.conf file [globals] section. -</para> - -<important><para> -Never use both <command>wins support = yes</command> together -with <command>wins server = a.b.c.d</command> -particularly not using it's own IP address. -Specifying both will cause &nmbd; to refuse to start! -</para></important> - -</sect1> - -<sect1> -<title>Do NOT use more than one (1) protocol on MS Windows machines</title> - -<para> -A very common cause of browsing problems results from installing more than -one protocol on an MS Windows machine. -</para> - -<para> -Every NetBIOS machine takes part in a process of electing the LMB (and DMB) -every 15 minutes. A set of election criteria is used to determine the order -of precidence for winning this election process. A machine running Samba or -Windows NT will be biased so that the most suitable machine will predictably -win and thus retain it's role. -</para> - -<para> -The election process is "fought out" so to speak over every NetBIOS network -interface. In the case of a Windows 9x machine that has both TCP/IP and IPX -installed and has NetBIOS enabled over both protocols the election will be -decided over both protocols. As often happens, if the Windows 9x machine is -the only one with both protocols then the LMB may be won on the NetBIOS -interface over the IPX protocol. Samba will then lose the LMB role as Windows -9x will insist it knows who the LMB is. Samba will then cease to function -as an LMB and thus browse list operation on all TCP/IP only machines will -fail. -</para> - -<para><emphasis> -Windows 95, 98, 98se, Me are referred to generically as Windows 9x. -The Windows NT4, 2000, XP and 2003 use common protocols. These are roughly -referred to as the WinNT family, but it should be recognised that 2000 and -XP/2003 introduce new protocol extensions that cause them to behave -differently from MS Windows NT4. Generally, where a server does NOT support -the newer or extended protocol, these will fall back to the NT4 protocols. -</emphasis></para> - -<para> -The safest rule of all to follow it this - USE ONLY ONE PROTOCOL! -</para> - -</sect1> - -<sect1> -<title>Name Resolution Order</title> - -<para> -Resolution of NetBIOS names to IP addresses can take place using a number -of methods. The only ones that can provide NetBIOS name_type information -are:</para> - -<simplelist> -<member>WINS: the best tool!</member> -<member>LMHOSTS: is static and hard to maintain.</member> -<member>Broadcast: uses UDP and can not resolve names across remote segments.</member> -</simplelist> - -<para> -Alternative means of name resolution includes:</para> -<simplelist> -<member>/etc/hosts: is static, hard to maintain, and lacks name_type info</member> -<member>DNS: is a good choice but lacks essential name_type info.</member> -</simplelist> - -<para> -Many sites want to restrict DNS lookups and want to avoid broadcast name -resolution traffic. The "name resolve order" parameter is of great help here. -The syntax of the "name resolve order" parameter is: -<programlisting> -name resolve order = wins lmhosts bcast host -</programlisting> -_or_ -<programlisting> -name resolve order = wins lmhosts (eliminates bcast and host) -</programlisting> -The default is: -<programlisting> -name resolve order = host lmhost wins bcast -</programlisting>. -where "host" refers the the native methods used by the Unix system -to implement the gethostbyname() function call. This is normally -controlled by <filename>/etc/host.conf</filename>, <filename>/etc/nsswitch.conf</filename> and <filename>/etc/resolv.conf</filename>. -</para> -</sect1> -</chapter> diff --git a/docs/docbook/projdoc/Browsing.sgml b/docs/docbook/projdoc/Browsing.sgml deleted file mode 100644 index ca2f6dc57b..0000000000 --- a/docs/docbook/projdoc/Browsing.sgml +++ /dev/null @@ -1,807 +0,0 @@ -<chapter id="improved-browsing"> -<chapterinfo> - <author> - <affiliation> - <orgname>Samba Team</orgname> - </affiliation> - </author> - - <pubdate> (5 July 1998) </pubdate> -</chapterinfo> - -<title>Improved browsing in samba</title> - -<sect1> -<title>Overview of browsing</title> - -<para> -SMB networking provides a mechanism by which clients can access a list -of machines in a network, a so-called <command>browse list</command>. This list -contains machines that are ready to offer file and/or print services -to other machines within the network. Thus it does not include -machines which aren't currently able to do server tasks. The browse -list is heavily used by all SMB clients. Configuration of SMB -browsing has been problematic for some Samba users, hence this -document. -</para> - -<para> -MS Windows 2000 and later, as with Samba 3 and later, can be -configured to not use NetBIOS over TCP/IP. When configured this way -it is imperative that name resolution (using DNS/LDAP/ADS) be correctly -configured and operative. Browsing will NOT work if name resolution -from SMB machine names to IP addresses does not function correctly. -</para> - -<para> -Where NetBIOS over TCP/IP is enabled use of a WINS server is highly -recommended to aid the resolution of NetBIOS (SMB) names to IP addresses. -WINS allows remote segment clients to obtain NetBIOS name_type information -that can NOT be provided by any other means of name resolution. -</para> - -</sect1> - -<sect1> -<title>Browsing support in samba</title> - -<para> -Samba facilitates browsing. The browsing is supported by &nmbd; -and is also controlled by options in the &smb.conf; file. -Samba can act as a local browse master for a workgroup and the ability -for samba to support domain logons and scripts is now available. -</para> - -<para> -Samba can also act as a domain master browser for a workgroup. This -means that it will collate lists from local browse masters into a -wide area network server list. In order for browse clients to -resolve the names they may find in this list, it is recommended that -both samba and your clients use a WINS server. -</para> - -<para> -Note that you should NOT set Samba to be the domain master for a -workgroup that has the same name as an NT Domain: on each wide area -network, you must only ever have one domain master browser per workgroup, -regardless of whether it is NT, Samba or any other type of domain master -that is providing this service. -</para> - -<note><para> -Nmbd can be configured as a WINS server, but it is not -necessary to specifically use samba as your WINS server. MS Windows -NT4, Server or Advanced Server 2000 or 2003 can be configured as -your WINS server. In a mixed NT/2000/2003 server and samba environment on -a Wide Area Network, it is recommended that you use the Microsoft -WINS server capabilities. In a samba-only environment, it is -recommended that you use one and only one Samba server as your WINS server. -</para></note> - -<para> -To get browsing to work you need to run nmbd as usual, but will need -to use the <command>workgroup</command> option in &smb.conf; -to control what workgroup Samba becomes a part of. -</para> - -<para> -Samba also has a useful option for a Samba server to offer itself for -browsing on another subnet. It is recommended that this option is only -used for 'unusual' purposes: announcements over the internet, for -example. See <command>remote announce</command> in the -&smb.conf; man page. -</para> -</sect1> - -<sect1> -<title>Problem resolution</title> - -<para> -If something doesn't work then hopefully the log.nmb file will help -you track down the problem. Try a debug level of 2 or 3 for finding -problems. Also note that the current browse list usually gets stored -in text form in a file called <filename>browse.dat</filename>. -</para> - -<para> -Note that if it doesn't work for you, then you should still be able to -type the server name as <filename>\\SERVER</filename> in filemanager then -hit enter and filemanager should display the list of available shares. -</para> - -<para> -Some people find browsing fails because they don't have the global -<command>guest account</command> set to a valid account. Remember that the -IPC$ connection that lists the shares is done as guest, and thus you must -have a valid guest account. -</para> - -<para><emphasis> -MS Windows 2000 and upwards (as with Samba) can be configured to disallow -anonymous (ie: Guest account) access to the IPC$ share. In that case, the -MS Windows 2000/XP/2003 machine acting as an SMB/CIFS client will use the -name of the currently logged in user to query the IPC$ share. MS Windows -9X clients are not able to do this and thus will NOT be able to browse -server resources. -</emphasis></para> - -<para> -The other big problem people have is that their broadcast address, -netmask or IP address is wrong (specified with the "interfaces" option -in &smb.conf;) -</para> -</sect1> - -<sect1> -<title>Browsing across subnets</title> -<para> -Since the release of Samba 1.9.17(alpha1) Samba has been -updated to enable it to support the replication of browse lists -across subnet boundaries. New code and options have been added to -achieve this. This section describes how to set this feature up -in different settings. -</para> - -<para> -To see browse lists that span TCP/IP subnets (ie. networks separated -by routers that don't pass broadcast traffic) you must set up at least -one WINS server. The WINS server acts as a DNS for NetBIOS names, allowing -NetBIOS name to IP address translation to be done by doing a direct -query of the WINS server. This is done via a directed UDP packet on -port 137 to the WINS server machine. The reason for a WINS server is -that by default, all NetBIOS name to IP address translation is done -by broadcasts from the querying machine. This means that machines -on one subnet will not be able to resolve the names of machines on -another subnet without using a WINS server. -</para> - -<para> -Remember, for browsing across subnets to work correctly, all machines, -be they Windows 95, Windows NT, or Samba servers must have the IP address -of a WINS server given to them by a DHCP server, or by manual configuration -(for Win95 and WinNT, this is in the TCP/IP Properties, under Network -settings) for Samba this is in the &smb.conf; file. -</para> - -<sect2> -<title>How does cross subnet browsing work ?</title> - -<para> -Cross subnet browsing is a complicated dance, containing multiple -moving parts. It has taken Microsoft several years to get the code -that achieves this correct, and Samba lags behind in some areas. -Samba is capable of cross subnet browsing when configured correctly. -</para> - -<para> -Consider a network set up as follows : -</para> - -<para> -<programlisting> - (DMB) - N1_A N1_B N1_C N1_D N1_E - | | | | | - ------------------------------------------------------- - | subnet 1 | - +---+ +---+ - |R1 | Router 1 Router 2 |R2 | - +---+ +---+ - | | - | subnet 2 subnet 3 | - -------------------------- ------------------------------------ - | | | | | | | | - N2_A N2_B N2_C N2_D N3_A N3_B N3_C N3_D - (WINS) -</programlisting> -</para> - -<para> -Consisting of 3 subnets (1, 2, 3) connected by two routers -(R1, R2) - these do not pass broadcasts. Subnet 1 has 5 machines -on it, subnet 2 has 4 machines, subnet 3 has 4 machines. Assume -for the moment that all these machines are configured to be in the -same workgroup (for simplicities sake). Machine N1_C on subnet 1 -is configured as Domain Master Browser (ie. it will collate the -browse lists for the workgroup). Machine N2_D is configured as -WINS server and all the other machines are configured to register -their NetBIOS names with it. -</para> - -<para> -As all these machines are booted up, elections for master browsers -will take place on each of the three subnets. Assume that machine -N1_C wins on subnet 1, N2_B wins on subnet 2, and N3_D wins on -subnet 3 - these machines are known as local master browsers for -their particular subnet. N1_C has an advantage in winning as the -local master browser on subnet 1 as it is set up as Domain Master -Browser. -</para> - -<para> -On each of the three networks, machines that are configured to -offer sharing services will broadcast that they are offering -these services. The local master browser on each subnet will -receive these broadcasts and keep a record of the fact that -the machine is offering a service. This list of records is -the basis of the browse list. For this case, assume that -all the machines are configured to offer services so all machines -will be on the browse list. -</para> - -<para> -For each network, the local master browser on that network is -considered 'authoritative' for all the names it receives via -local broadcast. This is because a machine seen by the local -master browser via a local broadcast must be on the same -network as the local master browser and thus is a 'trusted' -and 'verifiable' resource. Machines on other networks that -the local master browsers learn about when collating their -browse lists have not been directly seen - these records are -called 'non-authoritative'. -</para> - -<para> -At this point the browse lists look as follows (these are -the machines you would see in your network neighborhood if -you looked in it on a particular network right now). -</para> - -<para> -<programlisting> -Subnet Browse Master List ------- ------------- ---- -Subnet1 N1_C N1_A, N1_B, N1_C, N1_D, N1_E - -Subnet2 N2_B N2_A, N2_B, N2_C, N2_D - -Subnet3 N3_D N3_A, N3_B, N3_C, N3_D -</programlisting> -</para> - -<para> -Note that at this point all the subnets are separate, no -machine is seen across any of the subnets. -</para> - -<para> -Now examine subnet 2. As soon as N2_B has become the local -master browser it looks for a Domain master browser to synchronize -its browse list with. It does this by querying the WINS server -(N2_D) for the IP address associated with the NetBIOS name -WORKGROUP>1B<. This name was registerd by the Domain master -browser (N1_C) with the WINS server as soon as it was booted. -</para> - -<para> -Once N2_B knows the address of the Domain master browser it -tells it that is the local master browser for subnet 2 by -sending a MasterAnnouncement packet as a UDP port 138 packet. -It then synchronizes with it by doing a NetServerEnum2 call. This -tells the Domain Master Browser to send it all the server -names it knows about. Once the domain master browser receives -the MasterAnnouncement packet it schedules a synchronization -request to the sender of that packet. After both synchronizations -are done the browse lists look like : -</para> - -<para> -<programlisting> -Subnet Browse Master List ------- ------------- ---- -Subnet1 N1_C N1_A, N1_B, N1_C, N1_D, N1_E, - N2_A(*), N2_B(*), N2_C(*), N2_D(*) - -Subnet2 N2_B N2_A, N2_B, N2_C, N2_D - N1_A(*), N1_B(*), N1_C(*), N1_D(*), N1_E(*) - -Subnet3 N3_D N3_A, N3_B, N3_C, N3_D - -Servers with a (*) after them are non-authoritative names. -</programlisting> -</para> - -<para> -At this point users looking in their network neighborhood on -subnets 1 or 2 will see all the servers on both, users on -subnet 3 will still only see the servers on their own subnet. -</para> - -<para> -The same sequence of events that occured for N2_B now occurs -for the local master browser on subnet 3 (N3_D). When it -synchronizes browse lists with the domain master browser (N1_A) -it gets both the server entries on subnet 1, and those on -subnet 2. After N3_D has synchronized with N1_C and vica-versa -the browse lists look like. -</para> - -<para> -<programlisting> -Subnet Browse Master List ------- ------------- ---- -Subnet1 N1_C N1_A, N1_B, N1_C, N1_D, N1_E, - N2_A(*), N2_B(*), N2_C(*), N2_D(*), - N3_A(*), N3_B(*), N3_C(*), N3_D(*) - -Subnet2 N2_B N2_A, N2_B, N2_C, N2_D - N1_A(*), N1_B(*), N1_C(*), N1_D(*), N1_E(*) - -Subnet3 N3_D N3_A, N3_B, N3_C, N3_D - N1_A(*), N1_B(*), N1_C(*), N1_D(*), N1_E(*), - N2_A(*), N2_B(*), N2_C(*), N2_D(*) - -Servers with a (*) after them are non-authoritative names. -</programlisting> -</para> - -<para> -At this point users looking in their network neighborhood on -subnets 1 or 3 will see all the servers on all sunbets, users on -subnet 2 will still only see the servers on subnets 1 and 2, but not 3. -</para> - -<para> -Finally, the local master browser for subnet 2 (N2_B) will sync again -with the domain master browser (N1_C) and will recieve the missing -server entries. Finally - and as a steady state (if no machines -are removed or shut off) the browse lists will look like : -</para> - -<para> -<programlisting> -Subnet Browse Master List ------- ------------- ---- -Subnet1 N1_C N1_A, N1_B, N1_C, N1_D, N1_E, - N2_A(*), N2_B(*), N2_C(*), N2_D(*), - N3_A(*), N3_B(*), N3_C(*), N3_D(*) - -Subnet2 N2_B N2_A, N2_B, N2_C, N2_D - N1_A(*), N1_B(*), N1_C(*), N1_D(*), N1_E(*) - N3_A(*), N3_B(*), N3_C(*), N3_D(*) - -Subnet3 N3_D N3_A, N3_B, N3_C, N3_D - N1_A(*), N1_B(*), N1_C(*), N1_D(*), N1_E(*), - N2_A(*), N2_B(*), N2_C(*), N2_D(*) - -Servers with a (*) after them are non-authoritative names. -</programlisting> -</para> - -<para> -Synchronizations between the domain master browser and local -master browsers will continue to occur, but this should be a -steady state situation. -</para> - -<para> -If either router R1 or R2 fails the following will occur: -</para> - -<orderedlist> -<listitem> - <para> - Names of computers on each side of the inaccessible network fragments - will be maintained for as long as 36 minutes, in the network neighbourhood - lists. - </para> -</listitem> - -<listitem> - <para> - Attempts to connect to these inaccessible computers will fail, but the - names will not be removed from the network neighbourhood lists. - </para> -</listitem> - -<listitem> - <para> - If one of the fragments is cut off from the WINS server, it will only - be able to access servers on its local subnet, by using subnet-isolated - broadcast NetBIOS name resolution. The effects are similar to that of - losing access to a DNS server. - </para> -</listitem> -</orderedlist> -</sect2> -</sect1> - -<sect1> -<title>Setting up a WINS server</title> - -<para> -Either a Samba machine or a Windows NT Server machine may be set up -as a WINS server. To set a Samba machine to be a WINS server you must -add the following option to the &smb.conf; file on the selected machine : -in the [globals] section add the line -</para> - -<para> -<command> wins support = yes</command> -</para> - -<para> -Versions of Samba prior to 1.9.17 had this parameter default to -yes. If you have any older versions of Samba on your network it is -strongly suggested you upgrade to a recent version, or at the very -least set the parameter to 'no' on all these machines. -</para> - -<para> -Machines with <command>wins support = yes</command> will keep a list of -all NetBIOS names registered with them, acting as a DNS for NetBIOS names. -</para> - -<para> -You should set up only ONE wins server. Do NOT set the -<command>wins support = yes</command> option on more than one Samba -server. -</para> - -<para> -To set up a Windows NT Server as a WINS server you need to set up -the WINS service - see your NT documentation for details. Note that -Windows NT WINS Servers can replicate to each other, allowing more -than one to be set up in a complex subnet environment. As Microsoft -refuse to document these replication protocols Samba cannot currently -participate in these replications. It is possible in the future that -a Samba->Samba WINS replication protocol may be defined, in which -case more than one Samba machine could be set up as a WINS server -but currently only one Samba server should have the -<command>wins support = yes</command> parameter set. -</para> - -<para> -After the WINS server has been configured you must ensure that all -machines participating on the network are configured with the address -of this WINS server. If your WINS server is a Samba machine, fill in -the Samba machine IP address in the "Primary WINS Server" field of -the "Control Panel->Network->Protocols->TCP->WINS Server" dialogs -in Windows 95 or Windows NT. To tell a Samba server the IP address -of the WINS server add the following line to the [global] section of -all &smb.conf; files : -</para> - -<para> -<command>wins server = >name or IP address<</command> -</para> - -<para> -where >name or IP address< is either the DNS name of the WINS server -machine or its IP address. -</para> - -<para> -Note that this line MUST NOT BE SET in the &smb.conf; file of the Samba -server acting as the WINS server itself. If you set both the -<command>wins support = yes</command> option and the -<command>wins server = <name></command> option then -nmbd will fail to start. -</para> - -<para> -There are two possible scenarios for setting up cross subnet browsing. -The first details setting up cross subnet browsing on a network containing -Windows 95, Samba and Windows NT machines that are not configured as -part of a Windows NT Domain. The second details setting up cross subnet -browsing on networks that contain NT Domains. -</para> - -</sect1> - -<sect1> -<title>Setting up Browsing in a WORKGROUP</title> - -<para> -To set up cross subnet browsing on a network containing machines -in up to be in a WORKGROUP, not an NT Domain you need to set up one -Samba server to be the Domain Master Browser (note that this is *NOT* -the same as a Primary Domain Controller, although in an NT Domain the -same machine plays both roles). The role of a Domain master browser is -to collate the browse lists from local master browsers on all the -subnets that have a machine participating in the workgroup. Without -one machine configured as a domain master browser each subnet would -be an isolated workgroup, unable to see any machines on any other -subnet. It is the presense of a domain master browser that makes -cross subnet browsing possible for a workgroup. -</para> - -<para> -In an WORKGROUP environment the domain master browser must be a -Samba server, and there must only be one domain master browser per -workgroup name. To set up a Samba server as a domain master browser, -set the following option in the [global] section of the &smb.conf; file : -</para> - -<para> -<command>domain master = yes</command> -</para> - -<para> -The domain master browser should also preferrably be the local master -browser for its own subnet. In order to achieve this set the following -options in the [global] section of the &smb.conf; file : -</para> - -<para> -<programlisting> -domain master = yes -local master = yes -preferred master = yes -os level = 65 -</programlisting> -</para> - -<para> -The domain master browser may be the same machine as the WINS -server, if you require. -</para> - -<para> -Next, you should ensure that each of the subnets contains a -machine that can act as a local master browser for the -workgroup. Any MS Windows NT/2K/XP/2003 machine should be -able to do this, as will Windows 9x machines (although these -tend to get rebooted more often, so it's not such a good idea -to use these). To make a Samba server a local master browser -set the following options in the [global] section of the -&smb.conf; file : -</para> - -<para> -<programlisting> -domain master = no -local master = yes -preferred master = yes -os level = 65 -</programlisting> -</para> - -<para> -Do not do this for more than one Samba server on each subnet, -or they will war with each other over which is to be the local -master browser. -</para> - -<para> -The <command>local master</command> parameter allows Samba to act as a -local master browser. The <command>preferred master</command> causes nmbd -to force a browser election on startup and the <command>os level</command> -parameter sets Samba high enough so that it should win any browser elections. -</para> - -<para> -If you have an NT machine on the subnet that you wish to -be the local master browser then you can disable Samba from -becoming a local master browser by setting the following -options in the <command>[global]</command> section of the -&smb.conf; file : -</para> - -<para> -<programlisting> -domain master = no -local master = no -preferred master = no -os level = 0 -</programlisting> -</para> - -</sect1> - -<sect1> -<title>Setting up Browsing in a DOMAIN</title> - -<para> -If you are adding Samba servers to a Windows NT Domain then -you must not set up a Samba server as a domain master browser. -By default, a Windows NT Primary Domain Controller for a Domain -name is also the Domain master browser for that name, and many -things will break if a Samba server registers the Domain master -browser NetBIOS name (<replaceable>DOMAIN</replaceable><1B>) -with WINS instead of the PDC. -</para> - -<para> -For subnets other than the one containing the Windows NT PDC -you may set up Samba servers as local master browsers as -described. To make a Samba server a local master browser set -the following options in the <command>[global]</command> section -of the &smb.conf; file : -</para> - -<para> -<programlisting> -domain master = no -local master = yes -preferred master = yes -os level = 65 -</programlisting> -</para> - -<para> -If you wish to have a Samba server fight the election with machines -on the same subnet you may set the <command>os level</command> parameter -to lower levels. By doing this you can tune the order of machines that -will become local master browsers if they are running. For -more details on this see the section <link linkend="browse-force-master"> -Forcing samba to be the master browser</link> -below. -</para> - -<para> -If you have Windows NT machines that are members of the domain -on all subnets, and you are sure they will always be running then -you can disable Samba from taking part in browser elections and -ever becoming a local master browser by setting following options -in the <command>[global]</command> section of the &smb.conf; -file : -</para> - -<para> -<command> - domain master = no - local master = no - preferred master = no - os level = 0 -</command> -</para> - -</sect1> - -<sect1 id="browse-force-master"> -<title>Forcing samba to be the master</title> - -<para> -Who becomes the <command>master browser</command> is determined by an election -process using broadcasts. Each election packet contains a number of parameters -which determine what precedence (bias) a host should have in the -election. By default Samba uses a very low precedence and thus loses -elections to just about anyone else. -</para> - -<para> -If you want Samba to win elections then just set the <command>os level</command> global -option in &smb.conf; to a higher number. It defaults to 0. Using 34 -would make it win all elections over every other system (except other -samba systems!) -</para> - -<para> -A <command>os level</command> of 2 would make it beat WfWg and Win95, but not MS Windows -NT/2K Server. A MS Windows NT/2K Server domain controller uses level 32. -</para> - -<para>The maximum os level is 255</para> - -<para> -If you want samba to force an election on startup, then set the -<command>preferred master</command> global option in &smb.conf; to "yes". Samba will -then have a slight advantage over other potential master browsers -that are not preferred master browsers. Use this parameter with -care, as if you have two hosts (whether they are windows 95 or NT or -samba) on the same local subnet both set with <command>preferred master</command> to -"yes", then periodically and continually they will force an election -in order to become the local master browser. -</para> - -<para> -If you want samba to be a <command>domain master browser</command>, then it is -recommended that you also set <command>preferred master</command> to "yes", because -samba will not become a domain master browser for the whole of your -LAN or WAN if it is not also a local master browser on its own -broadcast isolated subnet. -</para> - -<para> -It is possible to configure two samba servers to attempt to become -the domain master browser for a domain. The first server that comes -up will be the domain master browser. All other samba servers will -attempt to become the domain master browser every 5 minutes. They -will find that another samba server is already the domain master -browser and will fail. This provides automatic redundancy, should -the current domain master browser fail. -</para> - -</sect1> - -<sect1> -<title>Making samba the domain master</title> - -<para> -The domain master is responsible for collating the browse lists of -multiple subnets so that browsing can occur between subnets. You can -make samba act as the domain master by setting <command>domain master = yes</command> -in &smb.conf;. By default it will not be a domain master. -</para> - -<para> -Note that you should NOT set Samba to be the domain master for a -workgroup that has the same name as an NT Domain. -</para> - -<para> -When samba is the domain master and the master browser it will listen -for master announcements (made roughly every twelve minutes) from local -master browsers on other subnets and then contact them to synchronise -browse lists. -</para> - -<para> -If you want samba to be the domain master then I suggest you also set -the <command>os level</command> high enough to make sure it wins elections, and set -<command>preferred master</command> to "yes", to get samba to force an election on -startup. -</para> - -<para> -Note that all your servers (including samba) and clients should be -using a WINS server to resolve NetBIOS names. If your clients are only -using broadcasting to resolve NetBIOS names, then two things will occur: -</para> - -<orderedlist> -<listitem> - <para> - your local master browsers will be unable to find a domain master - browser, as it will only be looking on the local subnet. - </para> -</listitem> - -<listitem> - <para> - if a client happens to get hold of a domain-wide browse list, and - a user attempts to access a host in that list, it will be unable to - resolve the NetBIOS name of that host. - </para> -</listitem> -</orderedlist> - -<para> -If, however, both samba and your clients are using a WINS server, then: -</para> - -<orderedlist> -<listitem> - <para> - your local master browsers will contact the WINS server and, as long as - samba has registered that it is a domain master browser with the WINS - server, your local master browser will receive samba's ip address - as its domain master browser. - </para> -</listitem> - -<listitem> - <para> - when a client receives a domain-wide browse list, and a user attempts - to access a host in that list, it will contact the WINS server to - resolve the NetBIOS name of that host. as long as that host has - registered its NetBIOS name with the same WINS server, the user will - be able to see that host. - </para> -</listitem> -</orderedlist> - -</sect1> - -<sect1> -<title>Note about broadcast addresses</title> - -<para> -If your network uses a "0" based broadcast address (for example if it -ends in a 0) then you will strike problems. Windows for Workgroups -does not seem to support a 0's broadcast and you will probably find -that browsing and name lookups won't work. -</para> -</sect1> - -<sect1> -<title>Multiple interfaces</title> - -<para> -Samba now supports machines with multiple network interfaces. If you -have multiple interfaces then you will need to use the <command>interfaces</command> -option in &smb.conf; to configure them. -</para> -</sect1> -</chapter> |