WinNT Client Logon in Resource and Master Domain Environment

• Microsoft Windows NT Workstation versions 3.5, 3.51, and 4.0
• Microsoft Windows NT Server versions 3.5, 3.51, and 4.0

SUMMARY

When a computer running Windows NT Workstation or Server that is a member of a domain starts, it tries to establish a secure channel to a domain controller in its domain to validate its machine account. This occurs before the user is presented with the CTRL+ALT+DEL logon screen. If the domain that the Windows NT client is a member of trusts another domain, a user can log on to that trusted domain at the console.

If the user logs on to this trusted domain, the user's credentials are passed from the Windows NT client to a domain controller in its domain that it established a secure channel with at startup time. This resource domain controller then does pass-through authentication to a domain controller in the accounts or master domain that it established a secure channel with at startup time. If the user has a logon script, or if the client is Windows NT version 4.0 that implements Policies, the domain controller in the accounts domain that validated the user credentials through pass-through authentication, will also be used to service the log on script or Policies request.

MORE INFORMATION

The following Network Monitor frames summarize the critical communication between a computer running Windows NT Workstation and a domain controller in its domain, where its machine account resides:

   NAME QUERY FOR MEMBER WORKSTATION'S DOMAIN NAME:
   NBT: NS: Query req. for RANDYMCD       <1C>
   
   MEMBER WORKSTATION INITIATING SECURE CHANNEL WITH ITS DOMAIN CONTROLLER.
   BROADCASTS FIRST, THEN TRIES LIST RETURNED BY WINS:
   NETLOGON: SAM LOGON request from client
   
   MEMBER WORKSTATION ESTABLISHING SESSION WITH ITS DOMAIN CONTROLLER:
   SMB: C session setup & X, Username = , and C tree connect & X,
   Share = \\RANDYMC1\IPC$
   
   MEMBER WORKSTATION REQUESTING LIST OF TRUSTED DOMAINS:
   R_LSARPC: RPC Client call lsarpc:LsarEnumerateTrustedDomains(..)
   
   MEMBER WORKSTATION AUTHENTICATIONG ITS MACHINE ACCOUNT:
   SMB: C NT create & X, File = \NETLOGON
   R_LOGON: RPC Client call logon:NetrServerReqChallenge(..)
   R_LOGON: RPC Client call logon:NetrServerAuthenticate2(..)

   MEMBER WORKSTATION NAME QUERY FOR ITS DOMAIN CONTROLLER:
   NBT: NS: Query req. for RANDYMC1
   
   MEMBER WORKSTATION ESTABLISHING SESSION WITH ITS DOMAIN CONTROLLER:
   NBT: SS: Session Request, Dest:RANDYMC1, Source: RANDYMC3<00>, Len: 68
   SMB: C session setup & X, Username = , and C tree connect & X,
   Share = \\RANDYMC1\IPC$
   
   NOTE:  WINDOWS NT 4.0 UPDATES THE TRUSTED DOMAIN LIST CACHE EVERY 2
   MINUTES BY DEFAULT:
   R_LSARPC: RPC Client call lsarpc:LsarEnumerateTrustedDomains(..)
   
   MEMBER WORKSTATION PASSING ITS MACHINE NAME, USERNAME, AND TRUSTED
   DOMAIN CONTROLLER NAME TO ITS RESOURCE DOMAIN CONTROLLER:
   SMB: C NT create & X, File = \NETLOGON
   R_LOGON: RPC Client call logon:NetrLogonSamLogon(..)
   00160:  0000000000000900 0000420050005300   ..........B.P.S.
   00170:  490047004E004F00 4600460074000600   I.G.N.O.F.F.t...
   00180:  0000000000000600 0000450053005300   ..........E.S.S.
   00190:  44004F004D000900 0000000000000800   D.O.M...........
   001A0:  0000520041004E00 440059004D004300   ..R.A.N.D.Y.M.C.
   001B0:  33000300                            3...
   
   RESOURCE DOMAIN CONTROLLER PASSING CLIENTS CREDENTIALS TO TRUSTED
   ACCOUNTS DOMAIN CONTROLLER:
   MSRPC: c/o RPC Request:  call 0x4  opnum 0x2  context 0x0  hint 0x10A
   00160:  0000090000004200 5000530049004700   ......B.P.S.I.G.
   00170:  4E004F0046004600 0000060000000000   N.O.F.F.........
   00180:  0000060000004500 5300530044004F00   ......E.S.S.D.O.
   00190:  4D00090000000000 0000080000005200   M.............R.
   001A0:  41004E0044005900 4D00430033000300   A.N.D.Y.M.C.3...
   
   ACCOUNTS DOMAIN CONTROLLER PASSING AUTHENTICATION TO RESOURCE DOMAIN
   CONTROLLER ALONG WITH LOGON SCRIPT NAME:
   MSRPC: c/o RPC Response: call 0x4 context 0x0  hint 0x198  cancels 0x0
   00170:  0000000000000600 0000450053005300   ..........E.S.S.
   00180:  44004F004D000B00 0000000000000A00   D.O.M...........
   00190:  0000650073007300 64006F006D002E00   ..e.s.s.d.o.m...
   001A0:  6200610074000300 0000010200000700   b.a.t...........
   001B0:  0000000200000700 0000180400000700   ................
   001C0:  0000080000000000 0000070000004500   ..............E.
   001D0:  5300530044004F00 4D0031006F000A00   S.S.D.O.M.1.o...
   001E0:  0000000000000900 0000420050005300   ..........B.P.S.
   001F0:  490047004E004F00 4600460070000400   I.G.N.O.F.F.p...
   
   RESOURCE DOMAIN CONTROLLER PASSING POSITIVE AUTHENTICATION RESPONES TO
   MEMBER WORKSTATION ALONG WITH ACCOUNTS DOMAIN CONTROLLER COMPUTER NAME
   THAT DID THE AUTHENTICATION:
   R_LOGON: RPC Server response logon:NetrLogonSamLogon(..)
   00170:  0000000000000600 0000450053005300   ..........E.S.S.
   00180:  44004F004D000B00 0000000000000A00   D.O.M...........
   00190:  0000650073007300 64006F006D002E00   ..e.s.s.d.o.m...
   001A0:  6200610074000300 0000010200000700   b.a.t...........
   001B0:  0000000200000700 0000180400000700   ................
   001C0:  0000080000000000 0000070000004500   ..............E.
   001D0:  5300530044004F00 4D00310000000A00   S.S.D.O.M.1.....
   001E0:  0000000000000900 0000420050005300   ..........B.P.S.
   001F0:  490047004E004F00 4600460000000400   I.G.N.O.F.F.....
   
   MEMBER WORKSTATION NAME QUERY FOR ACCOUNTS DOMAIN CONTROLLER COMPUTER
   NAME:
   NBT: NS: Query req. for ESSDOM1
   
   MEMBER SERVER ESTABLISHING SESSION WITH ACCOUNTS DOMAIN CONTROLLER:
   SMB: C session setup & X, Username = ESSDOM, and C tree connect & X,
   Share = \\ESSDOM1\NETLOGON
   
   MEMBER WORKSTATION VERSION 4.0 CHECKING FOR A POLICY:
   SMB: C NT create & X, File = \ntconfig.pol
   
   MEMBER WORKSTATION CHECKING FOR ITS LOGON SCRIPT:
   SMB: C transact2 Query path info, File = \essdom.bat