1mailto(samba@samba.org) 2 3article(Joining an NT Domain with Samba 2.0)(Jeremy Allison, Samba Team)(7th October 1999) 4 5center(Joining an NT Domain with Samba 2.0) 6center(-----------------------------------) 7 8In order for a Samba-2 server to join an NT domain, you must first add 9the NetBIOS name of the Samba server to the NT domain on the PDC using 10Server Manager for Domains. This creates the machine account in the 11domain (PDC) SAM. Note that you should add the Samba server as a "Windows 12NT Workstation or Server", em(NOT) as a Primary or backup domain controller. 13 14Assume you have a Samba-2 server with a NetBIOS name of tt(SERV1) and are 15joining an NT domain called tt(DOM), which has a PDC with a NetBIOS name 16of tt(DOMPDC) and two backup domain controllers with NetBIOS names tt(DOMBDC1) 17and tt(DOMBDC2). 18 19In order to join the domain, first stop all Samba daemons and run the 20command 21 22tt(smbpasswd -j DOM -r DOMPDC) 23 24as we are joining the domain DOM and the PDC for that domain (the only 25machine that has write access to the domain SAM database) is DOMPDC. If this is 26successful you will see the message: 27 28tt(smbpasswd: Joined domain DOM.) 29 30in your terminal window. See the url(bf(smbpasswd))(smbpasswd.8.html) 31man page for more details. 32 33This command goes through the machine account password change 34protocol, then writes the new (random) machine account password for 35this Samba server into a file in the same directory in which an 36smbpasswd file would be stored - normally : 37 38tt(/usr/local/samba/private) 39 40The filename looks like this: 41 42tt(<NT DOMAIN NAME>.<Samba Server Name>.mac) 43 44The tt(.mac) suffix stands for machine account password file. So in 45our example above, the file would be called: 46 47tt(DOM.SERV1.mac) 48 49This file is created and owned by root and is not readable by any 50other user. It is the key to the domain-level security for your 51system, and should be treated as carefully as a shadow password file. 52 53Now, before restarting the Samba daemons you must edit your 54url(bf(smb.conf))(smb.conf.5.html) file to tell Samba it should now 55use domain security. 56 57Change (or add) your 58 59url(bf("security ="))(smb.conf.5.html#security) 60 61line in the url(bf([global]))(smb.conf.5.html#global) section of your 62url(bf(smb.conf))(smb.conf.5.html) to read: 63 64tt(security = domain) 65 66Next change the 67 68url(bf("workgroup ="))(smb.conf.5.html#workgroup) 69 70line in the url(bf([global]))(smb.conf.5.html#global) section to read: 71 72tt(workgroup = DOM) 73 74as this is the name of the domain we are joining. 75 76You must also have the parameter url(bf("encrypt passwords"))(smb.conf.5.html#encryptpasswords) 77set to tt("yes") in order for your users to authenticate to the 78NT PDC. 79 80Finally, add (or modify) a: 81 82url(bf("password server ="))(smb.conf.5.html#passwordserver) 83 84line in the url(bf([global]))(smb.conf.5.html#global) section to read: 85 86tt(password server = DOMPDC DOMBDC1 DOMBDC2) 87 88These are the primary and backup domain controllers Samba will attempt 89to contact in order to authenticate users. Samba will try to contact 90each of these servers in order, so you may want to rearrange this list 91in order to spread out the authentication load among domain 92controllers. 93 94Alternatively, if you want smbd to automatically determine the 95list of Domain controllers to use for authentication, you may set this line to be : 96 97tt(password server = *) 98 99This method, which is new in Samba 2.0.6 and above, allows Samba 100to use exactly the same mechanism that NT does. This method either broadcasts or 101uses a WINS database in order to find domain controllers to 102authenticate against. 103 104Finally, restart your Samba daemons and get ready for clients to begin 105using domain security! 106 107 108center(Why is this better than security = server?) 109center(------------------------------------------) 110 111Currently, domain security in Samba doesn't free you from having to 112create local Unix users to represent the users attaching to your 113server. This means that if domain user tt(DOM\fred) attaches to your 114domain security Samba server, there needs to be a local Unix user fred 115to represent that user in the Unix filesystem. This is very similar to 116the older Samba security mode url(bf("security=server"))(smb.conf.5.html#securityequalserver), where Samba would pass 117through the authentication request to a Windows NT server in the same 118way as a Windows 95 or Windows 98 server would. 119 120The advantage to domain-level security is that the authentication in 121domain-level security is passed down the authenticated RPC channel in 122exactly the same way that an NT server would do it. This means Samba 123servers now participate in domain trust relationships in exactly the 124same way NT servers do (i.e., you can add Samba servers into a 125resource domain and have the authentication passed on from a resource 126domain PDC to an account domain PDC. 127 128In addition, with url(bf("security=server"))(smb.conf.5.html#securityequalserver) every Samba daemon on a 129server has to keep a connection open to the authenticating server for 130as long as that daemon lasts. This can drain the connection resources 131on a Microsoft NT server and cause it to run out of available 132connections. With url(bf("security =domain"))(smb.conf.5.html#securityequaldomain), however, the Samba 133daemons connect to the PDC/BDC only for as long as is necessary to 134authenticate the user, and then drop the connection, thus conserving 135PDC connection resources. 136 137And finally, acting in the same manner as an NT server authenticating 138to a PDC means that as part of the authentication reply, the Samba 139server gets the user identification information such as the user SID, 140the list of NT groups the user belongs to, etc. All this information 141will allow Samba to be extended in the future into a mode the 142developers currently call appliance mode. In this mode, no local Unix 143users will be necessary, and Samba will generate Unix uids and gids 144from the information passed back from the PDC when a user is 145authenticated, making a Samba server truly plug and play in an NT 146domain environment. Watch for this code soon. 147 148em(NOTE:) Much of the text of this document was first published in the 149Web magazine url(bf("LinuxWorld"))(http://www.linuxworld.com) as the article url(bf("Doing the NIS/NT Samba"))(http://www.linuxworld.com/linuxworld/lw-1998-10/lw-10-samba.html). 150