From 8caf5fc07c716afad5644d64c80c3b41c143bc76 Mon Sep 17 00:00:00 2001 From: John Terpstra Date: Tue, 21 Jun 2005 07:54:37 +0000 Subject: More updates. (This used to be commit 438dbe5626eb57597a011b904e9bf5292eaf90bd) --- docs/Samba3-HOWTO/TOSHARG-NetworkBrowsing.xml | 701 +++++++++++++++++++------- 1 file changed, 519 insertions(+), 182 deletions(-) (limited to 'docs') diff --git a/docs/Samba3-HOWTO/TOSHARG-NetworkBrowsing.xml b/docs/Samba3-HOWTO/TOSHARG-NetworkBrowsing.xml index 6324bdfdd0..042f1c156f 100644 --- a/docs/Samba3-HOWTO/TOSHARG-NetworkBrowsing.xml +++ b/docs/Samba3-HOWTO/TOSHARG-NetworkBrowsing.xml @@ -11,6 +11,9 @@ Network Browsing +browsing across subnets +resolution of NetBIOS names +browse list handling This chapter contains detailed information as well as a 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 addresses; however, WINS is @@ -18,6 +21,10 @@ not involved in browse list handling except by way of name-to-address resolution +Windows 2000 +NetBIOS over TCP/IP +DNS +ADS MS Windows 2000 and later versions can be configured to operate with no NetBIOS over TCP/IP. Samba-3 and later versions also support this mode of operation. When the use of NetBIOS over TCP/IP has been disabled, the primary @@ -37,6 +44,8 @@ hope it never returns. NetBIOS +NetBIOS networking +fickle For many MS Windows network administrators, that statement sums up their feelings about NetBIOS networking precisely. For those who mastered NetBIOS networking, its fickle nature was just par for the course. For those who never quite managed to tame its @@ -53,6 +62,11 @@ features that make it such a persistent weed. +Network Basic Input/Output SystemNetBIOS +SMB +NetBIOS +TCP/IP +Windows network clients In this chapter we explore vital aspects of Server Message Block (SMB) networking with a particular focus on SMB as implemented through running NetBIOS (Network Basic Input/Output System) over TCP/IP. Since Samba does not implement SMB or NetBIOS over @@ -61,18 +75,26 @@ remember to use nothing but TCP/IP on all our MS Windows network clients. +WINS +MS WINS Samba provides the ability to implement a WINS (Windows Internetworking Name Server) and implements extensions to Microsoft's implementation of WINS. These extensions help Samba to effect stable WINS operations beyond the normal scope of MS WINS. +NetBIOS over TCP/IP +NetBIOS disabled +WINS WINS is exclusively a service that applies only to those systems that run NetBIOS over TCP/IP. MS Windows 200x/XP have the capacity to operate with support for NetBIOS disabled, in which case WINS is of no relevance. Samba supports this also. +NetBIOS disabled +DNS +WINS For those networks on which NetBIOS has been disabled (i.e., WINS is not required), the use of DNS is necessary for hostname resolution. @@ -83,6 +105,10 @@ the use of DNS is necessary for hostname resolution. What Is Browsing? +browsing +Network Neighborhood +shares +printers available To most people, browsing means they can see the MS Windows and Samba servers in the Network Neighborhood, and when the computer icon for a particular server is clicked, it opens up and shows the shares and printers available on the target server. @@ -103,6 +129,9 @@ The technologies (or methods) employed in making all of this work include: +browse list management +name resolution +nmbd The Samba application that controls browse list management and name resolution is called nmbd. The configuration parameters involved in nmbd's operation are: @@ -146,8 +175,12 @@ parameters is set, nmbd will still do its job. WINS -For Samba, the WINS Server and WINS Support are mutually exclusive options. When nmbd is -started it will fail to execute if both options are set in the &smb.conf; file. The nmbd +WINS Server +WINS Support +nmbd +mutually exclusive options +For Samba, the WINS Server and WINS Support are mutually exclusive options. When nmbd is +started it will fail to execute if both options are set in the &smb.conf; file. The nmbd understands that when it spawns an instance of itself to run as a WINS server that it has to use its own WINS server also. @@ -160,6 +193,8 @@ server also. SMB-based messaging NetBIOS +NetBIOS +phasing out NetBIOS All MS Windows networking uses SMB-based messaging. SMB messaging may be implemented with or without NetBIOS. MS Windows 200x supports NetBIOS over TCP/IP for backwards compatibility. Microsoft appears intent on phasing out NetBIOS support. @@ -215,6 +250,11 @@ configuration parameter called the NetBIOS node-type. There are four basic NetBI Hybrid +hybrid +enables NetBIOS over TCP/IP +WINS +broadcast-based +name resolution The default Windows network client (or server) network configuration enables NetBIOS over TCP/IP and b-node configuration. The use of WINS makes most sense with h-node (hybrid mode) operation so that in the event of a WINS breakdown or non-availability, the client can use broadcast-based name resolution. @@ -223,14 +263,16 @@ in the event of a WINS breakdown or non-availability, the client can use broadca LMBLocal Master Browser Local Master Browser -In those networks where Samba is the only SMB server technology, wherever possible -nmbd should be configured on one machine as the WINS -server. This makes it easy to manage the browsing environment. If each network -segment is configured with its own Samba WINS server, then the only way to -get cross-segment browsing to work is by using the - and the - -parameters to your &smb.conf; file. +SMB +nmbd +WINS +cross-segment browsing +network segment +In those networks where Samba is the only SMB server technology, wherever possible nmbd +should be configured on one machine as the WINS server. This makes it easy to manage the browsing environment. +If each network segment is configured with its own Samba WINS server, then the only way to get cross-segment +browsing to work is by using the and the parameters to your &smb.conf; file. @@ -249,6 +291,14 @@ not been of sufficient significance to inspire someone to pay a developer to com +WINS +MS-WINS replication +redundancy +DNS +NetBIOSless SMB over TCP/IP +local names +subnets +multiple WINS servers 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 @@ -264,6 +314,9 @@ clients are designed to use WINS. +broadcast messages +repeated intervals +across network segments 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 @@ -271,6 +324,7 @@ minutes to stabilize, particularly across network segments. +Windows 200x/XP When an MS Windows 200x/XP system attempts to resolve a host name to an IP address, it follows a defined path: @@ -301,6 +355,10 @@ When an MS Windows 200x/XP system attempts to resolve a host name to an IP addre +WINS +NetBIOS over TCP/IP +name lookups +DNS Given the nature of how the NetBIOS over TCP/IP protocol is implemented, only WINS is capable of resolving with any reliability name lookups for service oriented names such as TEMPTATION<1C> &smbmdash; a NetBIOS name query that seeks to find network logon servers. DNS has not concept of service oriented names such as @@ -327,17 +385,29 @@ TCP/IP-enabled systems. Only a few embedded TCP/IP systems do not support DNS. DNS +DDNS +ipconfig +Dynamic DNSDDNS Windows 200x/XP can register its hostname with a Dynamic DNS server (DDNS). It is possible to force register with a dynamic DNS server in Windows 200x/XP using ipconfig /registerdns. +ADS +DNS +severely impaired With Active Directory, a correctly functioning DNS server is absolutely essential. In the absence of a working DNS server that has been correctly configured, MS Windows clients and servers will be unable to locate each other, so network services consequently will be severely impaired. +raw SMB over TCP/IP +No NetBIOS layer +NetBIOS +domain member server +DNS +ADS Use of raw SMB over TCP/IP (No NetBIOS layer) can be done only with Active Directory domains. Samba is not an Active Directory domain controller: ergo, it is not possible to run Samba as a domain controller and at the same time not use NetBIOS. Where Samba is used as an Active Directory domain member server @@ -354,7 +424,11 @@ by the ADS environment. DNSActive Directory -Occasionally we hear from UNIX network administrators who want to use a UNIX-based dynamic DNS server in place +DDNS +ADS +SRV records +DNSSRV records +Occasionally we hear from UNIX network administrators who want to use a UNIX-based DDNS server in place of the Microsoft DNS server. While this might be desirable to some, the MS Windows 200x DNS server is autoconfigured to work with Active Directory. It is possible to use BIND version 8 or 9, but it will almost certainly be necessary to create service records (SRV records) so MS Active Directory clients can resolve @@ -363,6 +437,9 @@ Active Directory requires: +DDNS +ADS +BIND9 The use of DDNS is highly recommended with Active Directory, in which case the use of BIND9 is preferred for its ability to adequately support the SRV (service) records that are needed for Active Directory. Of course, when running ADS it makes sense to use Microsoft's own DDNS server because of the natural affinity between ADS @@ -542,6 +619,11 @@ noldor.quenya.org. 1200 IN A 10.1.1.17 How Browsing Functions +register NetBIOS names +LMHOSTS +DNS +WINS +WINS server address MS Windows machines register their NetBIOS names (i.e., the machine name for each service type in operation) on startup. 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, @@ -549,6 +631,9 @@ whether or not DNS for NetBIOS name resolution is enabled, and so on. +WINS server +name lookups +UDP 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 @@ -557,11 +642,22 @@ parameter). +WINS +UDP unicast +name resolution across routed networks 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. +LMB +local master browserLMB +WINS +LMHOSTS +DMB +browse list +election +election criteria During the startup process, an election takes place to create a local master browser (LMB) if one does not already exist. On each NetBIOS network one machine will be elected to function as the domain master browser (DMB). This domain browsing has nothing to do with MS security Domain Control. Instead, the DMB serves the @@ -573,6 +669,14 @@ criteria, will win the election as DMB. +WINS server +DMB +NetBIOS name type +n security context +network segment +authoritive +browse list maintainers +LMB Where a WINS server is used, the DMB registers its IP address with the WINS server using the name of the domain and the NetBIOS name type 1B. e.g., DOMAIN<1B>. All LMBs register their IP address with the WINS server, also with the name of the domain and the NetBIOS name type of 1D. The 1B name is unique to one @@ -582,16 +686,24 @@ they are on. The DMB is responsible for synchronizing the browse lists it obtain +name resolution 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 or addresses. +browsing intrinsics 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. +forced synchronization +LMB +bridges networks +cross-subnet browsing +DNS +/etc/hosts Samba supports a feature that allows forced synchronization of browse lists across routed networks using the parameter in the &smb.conf; file. This causes Samba to contact the LMB on a remote network and to request browse list synchronization. This effectively bridges two networks that @@ -606,6 +718,12 @@ be provided. This mechanism could be via DNS, /etc/hosts, a Configuring Workgroup Browsing +cross-subnet browsing +DMB +PDC +LMB +isolated workgroup +workgroup To configure cross-subnet browsing on a network containing machines in a workgroup, not an NT domain, you need to set up one Samba server to be the DMB (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 DMB is to collate the browse lists @@ -615,6 +733,7 @@ presence of a DMB that makes cross-subnet browsing possible for a workgroup. +DMB In a workgroup environment the DMB must be a Samba server, and there must only be one DMB per workgroup name. To set up a Samba server as a DMB, set the following option in the section of the &smb.conf; file: @@ -627,6 +746,8 @@ of the &smb.conf; file: +DMB +LMB The DMB should preferably be the LMB for its own subnet. In order to achieve this, set the following options in the section of the &smb.conf; file as shown in Domain Master Browser smb.conf @@ -644,10 +765,15 @@ linkend="dmbexample">Domain Master Browser smb.conf +DMB +WINS server The DMB may be the same machine as the WINS server, if necessary. +subnets +LMB +rebooted Next, you should ensure that each of the subnets contains a machine that can act as an LMB for the workgroup. Any MS Windows NT/200x/XP machine should be able to do this, as will Windows 9x/Me machines (although these tend to get rebooted more often, so it is not such a good idea to use them). To make a Samba server an LMB, @@ -667,11 +793,14 @@ set the following options in the section of th +LMB 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 LMB. +LMB +browser election The parameter allows Samba to act as a LMB. The causes nmbd to force a browser election on startup and the @@ -679,6 +808,7 @@ parameter sets Samba high enough so it should win any browser elections. +disable LMB If you have an NT machine on the subnet that you wish to be the LMB, you can disable Samba from becoming an LMB by setting the following options in the section of the &smb.conf; file as shown in smb.conf for Not Being a Master Browser. @@ -703,16 +833,22 @@ becoming an LMB by setting the following options in the section -of the &smb.conf; file as shown in Local Master Browser smb.conf +described. To make a Samba server a Local Master Browser, set the following options in the section of the &smb.conf; file as shown in Local Master Browser +smb.conf @@ -727,18 +863,22 @@ of the &smb.conf; file as shown in Local Master Browser s -If you wish to have a Samba server fight the election with machines on the same subnet, you -may set the parameter to lower levels. -By doing this you can tune the order of machines that will become LMBs if -they are running. For more details on this, refer to Section 9.4.3, Forcing Samba to Be the Master. +election +LMB +If you wish to have a Samba server fight the election with machines on the same subnet, you may set the + parameter to lower levels. By doing this you can tune the order of machines +that will become LMBs if they are running. For more details on this, refer to Forcing Samba to Be the Master. -If you have Windows NT machines that are members of the domain on all subnets and you are -sure they will always be running, you can disable Samba from taking part in browser elections -and ever becoming an LMB by setting the following options in the - section of the &smb.conf; file as shown in &smb.conf; -for Not Being a master browser +domain members +browser elections +LMB +If you have Windows NT machines that are members of the domain on all subnets and you are sure they will +always be running, you can disable Samba from taking part in browser elections and ever becoming an LMB by +setting the following options in the section of the &smb.conf; file as shown +in &smb.conf; for Not Being a master browser @@ -758,44 +898,66 @@ for Not Being a master browser Forcing Samba to Be the Master -Who becomes the master browser is determined by an election process using broadcasts. Each election packet contains a number of parameters -that determine what precedence (bias) a host should have in the election. By default Samba uses a low precedence and thus loses -elections to just about every Windows network server or client. +master browser +election process +broadcasts +election packet +bias +election +precedence +Who becomes the master browser is determined by an election process using broadcasts. Each election packet +contains a number of parameters that determine what precedence (bias) a host should have in the election. By +default Samba uses a low precedence and thus loses elections to just about every Windows network server or +client. -If you want Samba to win elections, set the -global option in &smb.conf; to a higher number. It defaults to 20. Using 34 would make it win -all elections over every other system (except other Samba systems). +If you want Samba to win elections, set the global option in &smb.conf; to a +higher number. It defaults to 20. Using 34 would make it win all elections over every other system (except +other Samba systems). -An of two would make it beat Windows for Workgroups and Windows 9x/Me, but not MS Windows -NT/200x Server. An MS Windows NT/200x Server domain controller uses level 32. The maximum os level is 255. +An of two would make it beat Windows for Workgroups and Windows 9x/Me, but +not MS Windows NT/200x Server. An MS Windows NT/200x Server domain controller uses level 32. The maximum os +level is 255. -If you want Samba to force an election on startup, set the - 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, because if you have two hosts (whether they are Windows 9x/Me or -NT/200x/XP or Samba) on the same local subnet both set with -to yes, then periodically and continually they will force an election in order -to become the LMB. +force an election +potential master browsers +local subnet +LMB +If you want Samba to force an election on startup, set the 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, because if +you have two hosts (whether they are Windows 9x/Me or NT/200x/XP or Samba) on the same local subnet both set +with to yes, then periodically and continually +they will force an election in order to become the LMB. -If you want Samba to be a DMB, then it is recommended that -you also set to yes, because -Samba will not become a DMB for the whole of your LAN or WAN if it is not also a -LMB on its own broadcast isolated subnet. +DMB +LAN +WAN +LMB +broadcast isolated subnet +If you want Samba to be a DMB, then it is recommended that you also set to yes, because Samba will not become a DMB for the whole of +your LAN or WAN if it is not also a LMB on its own broadcast isolated subnet. -It is possible to configure two Samba servers to attempt to become the DMB for a domain. The first server that comes -up will be the DMB. All other Samba servers will attempt to become the DMB every 5 minutes. They -will find that another Samba server is already the DMB and will fail. This provides automatic redundancy should -the current DMB fail. +DMB +automatic redundancy +UDP +network bandwidth +browser elections +It is possible to configure two Samba servers to attempt to become the DMB for a domain. The first server that +comes up will be the DMB. All other Samba servers will attempt to become the DMB every 5 minutes. They will +find that another Samba server is already the DMB and will fail. This provides automatic redundancy should the +current DMB fail. The network bandwidth overhead of browser elections is relatively small, requiring +approximately four UDP packets per machine per election. The maximum size of a UDP packet is 576 bytes. @@ -804,32 +966,39 @@ the current DMB fail. Making Samba the Domain Master -The domain master is responsible for collating the browse lists of multiple subnets so browsing can occur between subnets. You can -make Samba act as the domain master by setting yes -in &smb.conf;. By default it will not be a domain master. +DMB +collating +browse lists +browsing +The domain master browser is responsible for collating the browse lists of multiple subnets so browsing can +occur between subnets. You can make Samba act as the domain master browser by setting yes in &smb.conf;. By default it will not be a domain master browser. -Do not set Samba to be the domain master for a workgroup that has the same name as an NT/200x domain. -If Samba is configured to be the domain master for a workgroup that is present on the same -network as a Windows NT/200x domain that has the same name, network browsing problems will -certainly be experienced. +workgroup +network browsing problems +Do not set Samba to be the domain master for a workgroup that has the same name as an NT/200x domain. If +Samba is configured to be the domain master for a workgroup that is present on the same network as a Windows +NT/200x domain that has the same name, network browsing problems will certainly be experienced. -When Samba is the domain master and the master browser, it will listen for master -announcements (made roughly every 12 minutes) from LMBs on -other subnets and then contact them to synchronize browse lists. +When Samba is the domain master and the master browser, it will listen for master announcements (made roughly +every 12 minutes) from LMBs on other subnets and then contact them to synchronize browse lists. -If you want Samba to be the domain master, you should also set the - high enough to make sure it wins elections, and -set to yes, to -get Samba to force an election on startup. +win election +force election +If you want Samba to be the domain master, you should also set the high +enough to make sure it wins elections, and set to +yes, to get Samba to force an election on startup. +WINS server +resolve NetBIOS names All 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: @@ -837,12 +1006,15 @@ clients are only using broadcasting to resolve NetBIOS names, then two things wi +LMB +DMB LMBs will be unable to find a DMB because they will be looking only on the local subnet. +domain-wide browse list 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. @@ -850,6 +1022,7 @@ clients are only using broadcasting to resolve NetBIOS names, then two things wi +WINS If, however, both Samba and your clients are using a WINS server, then: @@ -876,6 +1049,7 @@ If, however, both Samba and your clients are using a WINS server, then: Note about Broadcast Addresses +zero-based broadcast If your network uses a zero-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 zeros broadcast, and you will probably find that browsing and name lookups will not work. @@ -885,10 +1059,33 @@ does not seem to support a zeros broadcast, and you will probably find that brow Multiple Interfaces +multiple network interfaces Samba supports machines with multiple network interfaces. If you have multiple interfaces, you will -need to use the option in &smb.conf; to configure them. +need to use the option in &smb.conf; to configure them. For example, the +machine you are working with has 4 network interfaces; eth0, eth1, eth2, eth3 and only +interfaces eth1 and eth4 should be used by Samba. In this case the +following &smb.conf; file entries would permit that intent: + +eth1, eth4 +Yes + +port 135 +port 137 +port 138 +port 139 +port 445 +UDP +TCP +The Yes is necessary to exclude TCP/IP session +services (ports 135, 139, and 445) over the interfaces that are not specified. Please be aware that +nmbd will listen for incoming UDP port 137 packets on the unlisted interfaces, but it will +not answer them. It will however send its broadcast packets over the unlisted interfaces. Total isolation of +ethernet interface requires the use of a firewall to block ports 137 and 138 (UDP), and ports 135, 139, and +445 (TCP) on all network interfaces that must not be able to access the Samba server. + + Use of the Remote Announce Parameter @@ -897,21 +1094,21 @@ The parameter of that all the NetBIOS names on a network get announced to a remote network. The syntax of the parameter is: -a.b.c.d [e.f.g.h] ... +192.168.12.23 [172.16.21.255] ... or -a.b.c.d/WORKGROUP [e.f.g.h/WORKGROUP] ... +192.168.12.23/MIDEARTH [172.16.21.255/ELVINDORF] ... where: - a.b.c.d and e.f.g.h + 192.168.12.23 and 172.16.21.255 LMBLocal Master Browser Local Master Browser is either the LMB IP address or the broadcast address of the remote network. - That is, the LMB is at 192.168.1.10, or the address could be given as 192.168.1.255 where the netmask + That is, the LMB is at 192.168.1.23, or the address could be given as 172.16.21.255 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. @@ -934,20 +1131,22 @@ where: Use of the Remote Browse Sync Parameter -The parameter of -&smb.conf; is used to announce to another LMB that it must synchronize its NetBIOS name list with our -Samba LMB. This works only if the Samba server that has this option is -simultaneously the LMB on its network segment. +LMB +synchronize +The parameter of &smb.conf; is used to announce to another LMB that +it must synchronize its NetBIOS name list with our Samba LMB. This works only if the Samba server that has +this option is simultaneously the LMB on its network segment. The syntax of the parameter is: -a.b.c.d +192.168.10.40 - -where a.b.c.d is either the IP address of the +LMB +remote segment +where 192.168.10.40 is either the IP address of the remote LMB or the network broadcast address of the remote segment. @@ -959,6 +1158,9 @@ remote LMB or the network broadcast address of the remote segment. WINS: The Windows Internetworking Name Server +WINS +name_type +LanManager-compatible Use of WINS (either Samba WINS or MS Windows NT Server WINS) is highly recommended. Every NetBIOS machine registers its name together with a name_type value for each of several types of service it has available. @@ -969,6 +1171,8 @@ by registering the server (the type 0x20) name. +NetBIOS name length +name_type 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 @@ -977,27 +1181,38 @@ name_type information). +WINS +registered +NetLogon service +lmhosts 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 cannot be used across network segments this type of +name resolution cannot be used across network segments, this type of information can only be provided via WINS or via a statically configured lmhosts file that must reside on all clients in the absence of WINS. -WINS also forces browse list synchronization by all -LMBs. LMBs must synchronize their browse list with the DMB, -and WINS helps the LMB to identify its DMB. By definition this -will work only within a single workgroup. Note that the DMB -has nothing to do with what is referred to as an MS Windows NT domain. The -latter is a reference to a security environment, while the DMB refers to the -master controller for browse list information only. +synchronization +LMB +DMB +WINS +browse list +WINS also forces browse list synchronization by all LMBs. LMBs must synchronize their browse list with the +DMB, and WINS helps the LMB to identify its DMB. By definition this will work only within a single workgroup. +Note that the DMB has nothing to do with what is referred to as an MS Windows NT domain. The latter is a +reference to a security environment, while the DMB refers to the master controller for browse list information +only. +WINS +TCP/IP protocol stack +WINS servers +name-to-address WINS will work correctly only if every client TCP/IP protocol stack is configured to use the WINS servers. Any client that is not configured to use the WINS server will continue to use only broadcast-based @@ -1014,21 +1229,21 @@ file [global] section. -To configure Samba to register with a WINS server, just add -a.b.c.d -to your &smb.conf; file section. +To configure Samba to register with a WINS server, just add 10.0.0.18 to your &smb.conf; file section. -Never use yes together -with a.b.c.d -particularly not using its own IP address. Specifying both will cause &nmbd; to refuse to start! +Never use yes together with 10.0.0.18 particularly not using its own IP address. Specifying both will cause &nmbd; +to refuse to start! WINS Server Configuration +WINS Either a Samba server or a Windows NT server machine may be set up as a WINS server. To configure a Samba server to be a WINS server, you must add to the &smb.conf; file on the selected Server the following line to @@ -1042,6 +1257,7 @@ the section: +Samba 1.9.17 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 @@ -1054,43 +1270,39 @@ all NetBIOS names registered with them, acting as a DNS for NetBIOS names. +only one WINS server It is strongly recommended to set up only one WINS server. Do not set the yes option on more than one Samba -server. +server on a network. replicationWINS -To configure Windows NT/200x Server as a WINS server, install and configure -the WINS service. See the Windows NT/200x documentation for details. -Windows NT/200x WINS servers can replicate to each other, allowing more -than one to be set up in a complex subnet environment. Because Microsoft -refuses to document the replication protocols, Samba cannot currently -participate in these replications. It is possible in the future that -a Samba-to-Samba WINS replication protocol may be defined, in which -case more than one Samba machine could be set up as a WINS server. -Currently only one Samba server should have the -yes parameter set. - - - -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 9x/Me or Windows NT/200x. To tell a Samba server the IP address -of the WINS server, add the following line to the section of -all &smb.conf; files: - - - +Windows NT/200x +WINS service +replication protocols +WINS server +To configure Windows NT/200x Server as a WINS server, install and configure the WINS service. See the Windows +NT/200x documentation for details. Windows NT/200x WINS servers can replicate to each other, allowing more +than one to be set up in a complex subnet environment. Because Microsoft refuses to document the replication +protocols, Samba cannot currently participate in these replications. It is possible in the future that a +Samba-to-Samba WINS replication protocol may be defined, in which case more than one Samba machine could be +set up as a WINS server. Currently only one Samba server should have the yes parameter set. + + + +WINS server +Primary WINS Server +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 9x/Me or Windows NT/200x. To tell a +Samba server the IP address of the WINS server, add the following line to the section of all &smb.conf; files: <name or IP address> - - - where <name or IP address> is either the DNS name of the WINS server machine or its IP address. @@ -1104,6 +1316,10 @@ server acting as the WINS server itself. If you set both the +cross-subnet browsing +Windows 9x/Me +Windows NT/200x +not part of domain There are two possible scenarios for setting up cross-subnet browsing. The first details setting up cross-subnet browsing on a network containing Windows 9x/Me, Samba, and Windows NT/200x machines that are not configured as @@ -1118,10 +1334,11 @@ browsing on networks that contain NT domains. replicationWINS -Samba-3 permits WINS replication through the use of the wrepld utility. -This tool is not currently in use because it is still in active development. -As soon as this tool becomes moderately functional, we will prepare man pages and enhance this -section of the documentation to provide usage and technical details. +WINS replication +Samba-3 permits WINS replication through the use of the wrepld utility. This tool is not +currently in use because it is still in development and has not been worked on for a long time. As soon as +this tool becomes moderately functional, we will prepare man pages and enhance this section of the +documentation to provide usage and technical details. @@ -1129,42 +1346,57 @@ section of the documentation to provide usage and technical details. Static WINS Entries -Adding static entries to your Samba WINS server is actually fairly easy. -All you have to do is add a line to wins.dat, typically -located in /usr/local/samba/var/locks or -/var/run/samba. +static WINS entries +wins.dat +/usr/local/samba/var/locks +/var/run/samba +Adding static entries to your Samba WINS server is actually fairly easy. All you have to do is add a line to +wins.dat, typically located in /usr/local/samba/var/locks or /var/run/samba. Entries in wins.dat take the form of: - "NAME#TYPE" TTL ADDRESS+ FLAGS - -where NAME is the NetBIOS name, TYPE is the NetBIOS type, TTL is the -time-to-live as an absolute time in seconds, ADDRESS+ is one or more -addresses corresponding to the registration, and FLAGS are the NetBIOS -flags for the registration. +TTL +time-to-liveTTL +where NAME is the NetBIOS name, TYPE is the NetBIOS type, TTL is the time-to-live as an absolute time in +seconds, ADDRESS+ is one or more addresses corresponding to the registration, and FLAGS are the NetBIOS flags +for the registration. A typical dynamic entry looks like this: -"MADMAN#03" 1055298378 192.168.1.2 66R +"MADMAN#03" 1155298378 192.168.1.2 66R - -To make it static, simply set the TTL to 0, like this: - +To make a NetBIOS name static (permanent), simply set the TTL to 0, like this: "MADMAN#03" 0 192.168.1.2 66R -Though this method works with early Samba-3 versions, there is a -possibility that it may change in future versions if WINS replication -is added. +NetBIOS flags +Broadcast node +Peer node +Meta node +Hybrid node +Permanent name +nameserv.h +The NetBIOS flags may be interpreted as additive hexadecimal values: 00 - Broadcast node registration, 20 - +Peer node registration, 40 - Meta node registration, 60 - Hybrid node registration, 02 - Permanent name, 04 - +Active name, 80 - Group name. The 'R' indications this is a registration record. Thus 66R means: Hyrbid node +active and permanent NetBIOS name. These values may be found in the nameserv.h header +file from the Samba source code repository. These are the values for the NB flags. + + + +WINS replication +Though this method works with early Samba-3 versions, there is a possibility that it may change in future +versions if WINS replication is added. @@ -1182,8 +1414,10 @@ for many new network administrators. Windows Networking Protocols -A common cause of browsing problems results from installing more than -one protocol on an MS Windows machine. +browsing problems +more than one protocol +A common cause of browsing problems results from the installation of more than one protocol on an MS Windows +machine. @@ -1191,6 +1425,8 @@ Do not use more than one protocol on MS Windows clients. +LMB +DMB 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 precedence for winning this election process. A machine running Samba or @@ -1199,18 +1435,23 @@ win and thus retain its role. -The election process is fought out over every NetBIOS network -interface. In the case of a Windows 9x/Me 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/Me 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 because Windows -9x/Me will insist it knows who the LMB is. Samba will then cease to function -as an LMB, and browse list operation on all TCP/IP-only machines will -therefore fail. +NetBIOS network interface +TCP/IP +IPX +LMB +Windows 9x/Me +TCP/IP-only +The election process is fought out, so to speak over every NetBIOS network interface. In +the case of a Windows 9x/Me 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/Me 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 because Windows 9x/Me will insist it knows who the LMB is. Samba will then +cease to function as an LMB, and browse list operation on all TCP/IP-only machines will therefore fail. +Windows 9x/Me +extended protocol Windows 95, 98, 98se, and Me are referred to generically as Windows 9x/Me. The Windows NT4, 200x, and XP use common protocols. These are roughly referred to as the Windows NT family, but it should be recognized that 2000 and @@ -1229,6 +1470,8 @@ The safest rule of all to follow is: Use only one protocol! Name Resolution Order +NetBIOS names +name_type 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: @@ -1245,10 +1488,12 @@ Alternative means of name resolution include: Static /etc/hosts &smbmdash; hard to maintain and lacks name_type info. -DNS &smbmdash; is a good choice but lacks essential name_type info. +DNS &smbmdash; is a good choice but lacks essential NetBIOS name_type information. +restrict DNS +name resolve order Many sites want to restrict DNS lookups and avoid broadcast name resolution traffic. The name resolve order parameter is of great help here. The syntax of the name resolve order parameter is: @@ -1263,6 +1508,7 @@ The default is: host lmhost wins bcast, +gethostbyname() function call where host refers to the native methods used by the UNIX system to implement the gethostbyname() function call. This is normally controlled by /etc/host.conf, /etc/nsswitch.conf and /etc/resolv.conf. @@ -1274,6 +1520,7 @@ controlled by /etc/host.conf, /etc/nsswitch.conf< Technical Overview of Browsing +SMB SMB networking provides a mechanism by which clients can access a list of machines in a network called . This list contains machines that are ready to offer file and/or print services @@ -1285,6 +1532,9 @@ document. +NetBIOS over TCP/IP +DNS/LDAP/ADS +name resolution MS Windows 2000 and later versions, as with Samba-3 and later versions, 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 @@ -1293,6 +1543,8 @@ from SMB machine names to IP addresses does not function correctly. +NetBIOS +WINS 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 @@ -1303,6 +1555,10 @@ that cannot be provided by any other means of name resolution. Browsing Support in Samba +browsing +LMB +domain logons +scripts Samba facilitates browsing. The browsing is supported by &nmbd; and is also controlled by options in the &smb.conf; file. Samba can act as an LMB for a workgroup, and the ability @@ -1310,6 +1566,9 @@ to support domain logons and scripts is now available. +DMB for a workgroup +LMB +WINS Samba can also act as a DMB for a workgroup. This means that it will collate lists from LMBs into a wide-area network server list. In order for browse clients to @@ -1318,6 +1577,7 @@ both Samba and your clients use a WINS server. +domain master Do 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 DMB per workgroup, regardless of whether it is NT, Samba, @@ -1325,6 +1585,8 @@ or any other type of domain master that is providing this service. +nmbd +WINS server 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 200x can be configured as @@ -1335,12 +1597,14 @@ recommended that you use one and only one Samba server as the WINS server. -To get browsing to work, you need to run nmbd as usual, but must +nmbd +To get browsing to work, you need to run nmbd as usual, but must use the option in &smb.conf; to control what workgroup Samba becomes a part of. +browsing another subnet 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 used only for unusual purposes: announcements over the Internet, for @@ -1353,6 +1617,8 @@ example. See in the Problem Resolution +log.nmbd +browse.dat If something does not work, the log.nmbd file will help to track down the problem. Try a of 2 or 3 for finding problems. Also note that the current browse list usually gets stored @@ -1360,18 +1626,26 @@ in text form in a file called browse.dat. +\\SERVER +filemanager If it does not work, you should still be able to type the server name as \\SERVER in filemanager, then press enter, and filemanager should display the list of available shares. +IPC$ +guest account Some people find browsing fails because they do not have the global set to a valid account. Remember that the IPC$ connection that lists the shares is done as guest and so you must have a valid guest account. +guest account +anonymous access +IPC$ +browse server resources MS Windows 2000 and later (as with Samba) can be configured to disallow anonymous (i.e., 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 @@ -1381,6 +1655,7 @@ server resources. +broadcast address The other big problem people have is that their broadcast address, netmask, or IP address is wrong (specified with the option in &smb.conf;) @@ -1392,40 +1667,59 @@ in &smb.conf;) replicationbrowse lists -Since the release of Samba 1.9.17 (alpha1), Samba has supported the -replication of browse lists across subnet boundaries. This section -describes how to set this feature up in different settings. +browse across subnet +Since the release of Samba 1.9.17 (alpha1), Samba has supported the replication of browse lists across subnet +boundaries. This section describes how to set this feature up in different settings. -To see browse lists that span TCP/IP subnets (i.e., networks separated -by routers that do not pass broadcast traffic), you must set up at least -one WINS server. The WINS server acts as a DNS for NetBIOS names. This will -allow NetBIOS name-to-IP address translation to be completed by a direct -query of the WINS server. This is done via a directed UDP packet on -port 137 to the WINS server machine. The WINS server avoids the necessity -of default NetBIOS name-to-IP address translation, which is done -using UDP 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. +browse lists +broadcast traffic +UDP +WINS +remote announce +remote browse sync +To see browse lists that span TCP/IP subnets (i.e., networks separated by routers that do not pass broadcast +traffic), you must set up at least one WINS server. The WINS server acts as a DNS for NetBIOS names. This will +allow NetBIOS name-to-IP address translation to be completed by a direct query of the WINS server. This is +done via a directed UDP packet on port 137 to the WINS server machine. The WINS server avoids the necessity of +default NetBIOS name-to-IP address translation, which is done using UDP 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. The Samba hacks, remote browse sync, and remote +announce are designed to get around the natural limitations that provent UDP broadcast +propagation. The hacks are not a universal solution and they should not be used in place of WINS, they are +considered last resort methods. + + + +DHCP +browsing across subnets +WINS +Network settings +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 Windows 9x/Me and Windows NT/200x/XP, this is in the TCP/IP Properties, under Network +settings; for Samba, this is in the &smb.conf; file. -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 Windows 9x/Me and Windows NT/200x/XP, this is in the TCP/IP Properties, under Network -settings; for Samba, this is in the &smb.conf; file. +NetBIOS over TCP/IP +ADS +DNS +It is possible to operate Samba-3 without NetBIOS over TCP/IP. If you do this, be warned that if used outside +of MS ADS, this will forgo network browsing support. ADS permits network browsing support through DNS, +providing appropriate DNS records are inserted for all Samba servers. Behavior of Cross-Subnet Browsing -Cross-subnet browsing is a complicated dance, containing multiple -moving parts. It has taken Microsoft several years to get the code -that correctly achieves this, and Samba lags behind in some areas. -Samba is capable of cross-subnet browsing when configured correctly. +cross-subnet browsing +complicated +Cross-subnet browsing is a complicated dance, containing multiple moving parts. It has taken Microsoft several +years to get the code that correctly achieves this, and Samba lags behind in some areas. Samba is capable of +cross-subnet browsing when configured correctly. @@ -1438,18 +1732,21 @@ Consider a network set up as in Cross-Subnet Browsing -This consists of three subnets (1, 2, 3) connected by two routers -(R1, R2), which do not pass broadcasts. Subnet 1 has five machines -on it, subnet 2 has four machines, and subnet 3 has four machines. Assume -for the moment that all machines are configured to be in the -same workgroup (for simplicity's sake). Machine N1_C on subnet 1 -is configured as the DMB (i.e., it will collate the -browse lists for the workgroup). Machine N2_D is configured as -a WINS server, and all the other machines are configured to register -their NetBIOS names with it. +broadcasts +DMB +WINS +This consists of three subnets (1, 2, 3) connected by two routers (R1, R2), which do not pass broadcasts. +Subnet 1 has five machines on it, subnet 2 has four machines, and subnet 3 has four machines. Assume for the +moment that all machines are configured to be in the same workgroup (for simplicity's sake). Machine N1_C on +subnet 1 is configured as the DMB (i.e., it will collate the browse lists for the workgroup). Machine N2_D is +configured as a WINS server, and all the other machines are configured to register their NetBIOS names with +it. +master browsers +LMB +DMB As these machines are booted up, elections for master browsers 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 @@ -1459,6 +1756,8 @@ LMB on subnet 1 because it is set up as DMB. +LMB +browse list On each of the three networks, machines that are configured to offer sharing services will broadcast that they are offering these services. The LMB on each subnet will @@ -1470,6 +1769,11 @@ will be on the browse list. +LMB +authoritative +verifiable +trusted +non-authoritative For each network, the LMB on that network is considered authoritative for all the names it receives via local broadcast. This is because a machine seen by the LMB @@ -1482,6 +1786,7 @@ called non-authoritative. +network neighborhood At this point the browse lists appear as shown in Browse Subnet Example 1 (these are the machines you would see in your network neighborhood if you looked in it on a particular network right now). @@ -1508,6 +1813,10 @@ At this point all the subnets are separate, and no machine is seen across any of +DMB +LMB +synchronize +WINS Now examine subnet 2 in Browse Subnet Example 2. As soon as N2_B has become the LMB, it looks for a DMB with which to synchronize its browse list. It does this by querying the WINS server @@ -1517,6 +1826,10 @@ WORKGROUP<1B>. This name was registered by the DMB +MasterAnnouncement +NetServerEnum2 +synchronization +browse lists Once N2_B knows the address of the DMB, it tells it that is the LMB for subnet 2 by sending a MasterAnnouncement packet as a UDP port 138 packet. @@ -1549,16 +1862,19 @@ N1_B(*), N1_C(*), N1_D(*), N1_E(*) +non-authoritative Servers with an (*) after them are non-authoritative names. +Network Neighborhood 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 see only the servers on their own subnet. +DMB The same sequence of events that occurred for N2_B now occurs for the LMB on subnet 3 (N3_D). When it synchronizes browse lists with the DMB (N1_A) @@ -1600,6 +1916,9 @@ subnet 2 will still see only the servers on subnets 1 and 2, but not 3. +LMB +DMB +browse lists Finally, the LMB for subnet 2 (N2_B) will sync again with the DMB (N1_C) and will receive the missing server entries. Finally, as when a steady state (if no machines @@ -1649,6 +1968,7 @@ If either router R1 or R2 fails, the following will occur: +Network Neighborhood Names of computers on each side of the inaccessible network fragments will be maintained for as long as 36 minutes in the Network Neighborhood lists. @@ -1664,6 +1984,9 @@ If either router R1 or R2 fails, the following will occur: +WINS +NetBIOS name resolution +DNS server If one of the fragments is cut off from the WINS server, it will only be able to access servers on its local subnet using subnet-isolated broadcast NetBIOS name resolution. The effect is similar to that of @@ -1679,6 +2002,8 @@ If either router R1 or R2 fails, the following will occur: Common Errors +browsing problems +name resolution Many questions are asked on the mailing lists regarding browsing. The majority of browsing problems originate from incorrect configuration of NetBIOS name resolution. Some are of particular note. @@ -1689,6 +2014,9 @@ particular note. flush name cache +nmbd +NetBIOS name cache +rogue machine Samba's nmbd process controls all browse list handling. Under normal circumstances it is safe to restart nmbd. This will effectively flush the Samba NetBIOS name cache and cause it to be rebuilt. This does not make certain that a rogue machine name will not reappear @@ -1748,6 +2076,7 @@ Windows Explorer will respond and displays files and directories without problem +cmd But, the share is immediately available from a command shell (cmd, followed by exploration with DOS command. Is this a Samba problem, or is it a Windows problem? How can I solve this? @@ -1762,6 +2091,9 @@ Here are a few possibilities: bad hardware WebClient +defective hardware +Bad networking hardware +data corruption Most common defective hardware problems center around low cost or defective hubs, routers, network interface controllers (NICs), and bad wiring. If one piece of hardware is defective, the whole network may suffer. Bad networking hardware can cause data corruption. Most bad @@ -1773,6 +2105,7 @@ Here are a few possibilities: The Windows XP WebClient +network browsing problems A number of sites have reported similar slow network browsing problems and found that when the WebClient service is turned off, the problem disappears. This is certainly something that should be explored because it is a simple solution &smbmdash; if it works. @@ -1782,6 +2115,8 @@ Here are a few possibilities: Inconsistent WINS Configuration +WINS Configuration +WINS server This type of problem is common when one client is configured to use a WINS server (that is a TCP/IP configuration setting) and there is no WINS server on the network. Alternatively, this will happen if there is a WINS server and Samba is not configured to use it. The use of @@ -1794,6 +2129,8 @@ Here are a few possibilities: Incorrect DNS Configuration +DNS Configuration +NetBIOS over TCP/IP disabled If use of NetBIOS over TCP/IP is disabled, Active Directory is in use and the DNS server has been incorrectly configured. For further information refer to DNS and Active Directory. -- cgit