11 WORKING WITH COMPUTER ACCOUNTS Chapter 8

Chapter 8: WORKING WITH COMPUTER ACCOUNTS2 CHAPTER OVERVIEW Describe the process of adding a computer to an Active Directory domain Create and manage computer objects Troubleshoot computer accounts Describe the process of adding a computer to an Active Directory domain Create and manage computer objects Troubleshoot computer accounts

Chapter 8: WORKING WITH COMPUTER ACCOUNTS3 UNDERSTANDING COMPUTER OBJECTS Logical representation in Active Directory of the physical computer object A mean to track computers belonging to the domain User cannot log on to the domain from a computer without a computer account in Active Directory Can be granted permissions to other objects Inherit group policy settings from domains, sites, and OUs Can be made a member of a security and distribution group and inherit group permissions Logical representation in Active Directory of the physical computer object A mean to track computers belonging to the domain User cannot log on to the domain from a computer without a computer account in Active Directory Can be granted permissions to other objects Inherit group policy settings from domains, sites, and OUs Can be made a member of a security and distribution group and inherit group permissions

Chapter 8: WORKING WITH COMPUTER ACCOUNTS4 CREATING COMPUTER OBJECTS Computer object must exist in Active Directory before computer can be joined to the domain. Computer object can be created using Active Directory Users and Computers or a command-line tool such as Dsadd. Computer account can also be created during the domain joining process. Computer account SID is stored in Active Directory computer account object Prevent a rogue computer from accessing the network Computer object must exist in Active Directory before computer can be joined to the domain. Computer object can be created using Active Directory Users and Computers or a command-line tool such as Dsadd. Computer account can also be created during the domain joining process. Computer account SID is stored in Active Directory computer account object Prevent a rogue computer from accessing the network

Chapter 8: WORKING WITH COMPUTER ACCOUNTS5 COMPUTER ACCOUNT AUTHENTICATION Computer authenticate before user account is authenticated Client computer and Domain Controller mutual authentication Authenticate using computer account and password Account name Up to 63 characters Pre-Windows 2000 the first 15 characters Password is generated automatically and kept hidden Account name up to 63 characters Pre-Windows 2000 the first 15 characters Computer authenticate before user account is authenticated Client computer and Domain Controller mutual authentication Authenticate using computer account and password Account name Up to 63 characters Pre-Windows 2000 the first 15 characters Password is generated automatically and kept hidden Account name up to 63 characters Pre-Windows 2000 the first 15 characters

Chapter 8: WORKING WITH COMPUTER ACCOUNTS6 CREATING COMPUTER OBJECTS USING ACTIVE DIRECTORY USERS AND COMPUTERS Permission Requirements: Administrators Account Operators Delegated control

Chapter 8: WORKING WITH COMPUTER ACCOUNTS7 CREATING COMPUTER OBJECTS USING DSADD.EXE Allows computer account creation to be scripted Provides a mechanism to create large amounts of computer accounts at one time Allows computer account creation to be scripted Provides a mechanism to create large amounts of computer accounts at one time Example: DSAdd computer “CN=MyComputer,CN=Computers,DC=MyCompany,DC=Com”

Chapter 8: WORKING WITH COMPUTER ACCOUNTS8 CREATING COMPUTER OBJECTS USING NETDOM.EXE Command-line utility Simpler to use than Dsadd Must be extracted from the support.cab archive in the \Support\Tools folder on the Windows Server 2003 installation CD or install by running suptools.msi Command-line utility Simpler to use than Dsadd Must be extracted from the support.cab archive in the \Support\Tools folder on the Windows Server 2003 installation CD or install by running suptools.msi Example: Netdom add MyComputer /Domain:Contoso.com /UserD:Admin /PasswordD:Secret /OU:Organization

Chapter 8: WORKING WITH COMPUTER ACCOUNTS9 JOINING COMPUTERS TO A DOMAIN

Chapter 8: WORKING WITH COMPUTER ACCOUNTS10 JOINING A DOMAIN USING NETDOM.EXE Allows computers to be joined to the domain from a command line Allows scripts to be developed to streamline the process of joining a computer to a domain Netdom join ….. Allows computers to be joined to the domain from a command line Allows scripts to be developed to streamline the process of joining a computer to a domain Netdom join …..

Chapter 8: WORKING WITH COMPUTER ACCOUNTS11 CREATING COMPUTER OBJECTS WHILE JOINING THE DOMAIN

Chapter 8: WORKING WITH COMPUTER ACCOUNTS12 JOINING A DOMAIN DURING OPERATING SYSTEM INSTALLATION

Chapter 8: WORKING WITH COMPUTER ACCOUNTS13 LOCATING COMPUTER OBJECTS The Computers container The Domain Controllers OU The Computers container The Domain Controllers OU

Chapter 8: WORKING WITH COMPUTER ACCOUNTS14 LOCATING DC COMPUTER OBJECTS Computer accounts for domain controllers are placed in the system-created domain controllers OU by default. The Default Domain Controllers Policy GPO is applied to the container. Computer accounts for domain controllers are placed in the system-created domain controllers OU by default. The Default Domain Controllers Policy GPO is applied to the container.

Chapter 8: WORKING WITH COMPUTER ACCOUNTS15 LOCATING OTHER COMPUTER OBJECTS Non–domain-controller computer accounts are placed in the Computers system-created container by default. Computer container does not support group policy Non–domain-controller computer accounts are placed in the Computers system-created container by default. Computer container does not support group policy

Chapter 8: WORKING WITH COMPUTER ACCOUNTS16 REDIRECTING COMPUTER OBJECTS Allows an alternative default location for computer accounts to be specified. Use the Redircmp.exe command-line utility. Works only on Windows Server 2003 domain functional level. Automatically redirects all computer accounts Can be overridden by explicit computer account creation commands. Allows an alternative default location for computer accounts to be specified. Use the Redircmp.exe command-line utility. Works only on Windows Server 2003 domain functional level. Automatically redirects all computer accounts Can be overridden by explicit computer account creation commands. Example: Redircmp ou=Workstations,DC=contoso,DC=com

Chapter 8: WORKING WITH COMPUTER ACCOUNTS17 MANAGING COMPUTER OBJECTS Computer objects have properties. Can be viewed and configured through Active Directory Users and Computers Computer objects have properties. Can be viewed and configured through Active Directory Users and Computers

Chapter 8: WORKING WITH COMPUTER ACCOUNTS18 MODIFYING COMPUTER OBJECT PROPERTIES

Chapter 8: WORKING WITH COMPUTER ACCOUNTS19 DELETING, DISABLING, AND RESETTING COMPUTER OBJECTS Deleting Removes the computer account from Active Directory Disabling Prevents the computer from being used to log on to the domain Resetting Reestablishes relationship between a computer and Active Directory Deleting Removes the computer account from Active Directory Disabling Prevents the computer from being used to log on to the domain Resetting Reestablishes relationship between a computer and Active Directory

Chapter 8: WORKING WITH COMPUTER ACCOUNTS20 DELETING COMPUTER OBJECTS Manually through Active Directory Users and Computers Automatically by changing the domain membership on the computer Using a command-line tool such as Dsrm Manually through Active Directory Users and Computers Automatically by changing the domain membership on the computer Using a command-line tool such as Dsrm

Chapter 8: WORKING WITH COMPUTER ACCOUNTS21 DISABLING COMPUTER OBJECTS

Chapter 8: WORKING WITH COMPUTER ACCOUNTS22 RESETTING A COMPUTER OBJECT Necessary when replacing or upgrading a computer system Allows an appropriately named new system to use an existing computer account Allows computer account password on the computer to be synchronized with computer account password stored on the domain controller Necessary when replacing or upgrading a computer system Allows an appropriately named new system to use an existing computer account Allows computer account password on the computer to be synchronized with computer account password stored on the domain controller

Chapter 8: WORKING WITH COMPUTER ACCOUNTS23 MANAGING REMOTE COMPUTERS Allows you to perform management tasks across the network Actually a shortcut to the Computer Management MMC snap-in Allows you to perform management tasks across the network Actually a shortcut to the Computer Management MMC snap-in

Chapter 8: WORKING WITH COMPUTER ACCOUNTS24 MANAGING COMPUTER OBJECTS FROM THE COMMAND LINE Dsmod Used to modify existing computer account objects Dsrm Used to remove computer account objects from Active Directory Dsmod Used to modify existing computer account objects Dsrm Used to remove computer account objects from Active Directory

Chapter 8: WORKING WITH COMPUTER ACCOUNTS25 MANAGING COMPUTER OBJECT PROPERTIES WITH DSMOD.EXE Can be used to modify properties of existing computer account objects Useful for creating scripts and batch files to automate changes Cannot be used to create or delete computer account objects Can be used to modify properties of existing computer account objects Useful for creating scripts and batch files to automate changes Cannot be used to create or delete computer account objects Example: DSMod computer CN=MyComp,CN=Computers,DC=Contoso,DC=com –reset

Chapter 8: WORKING WITH COMPUTER ACCOUNTS26 DELETING COMPUTER OBJECT PROPERTIES WITH DSRM.EXE Can be used to delete computer account objects from the command line Requires confirmation of deletion unless the - noprompt switch is used Can be used to delete computer account objects from the command line Requires confirmation of deletion unless the - noprompt switch is used Example: DSrm CN=MyComp,CN=Computers,DC=Contoso,DC=com

Chapter 8: WORKING WITH COMPUTER ACCOUNTS27 TROUBLESHOOTING COMPUTER ACCOUNTS: PROBLEMS Messages at logon indicate that a domain controller cannot be contacted, that the computer account might be missing, or that the trust between the computer and the domain has been lost. Error messages or entries in an event log indicate similar problems or suggest that passwords, trusts, secure channels, or relationships with the domain or a domain controller have failed. A computer account is missing in Active Directory. Messages at logon indicate that a domain controller cannot be contacted, that the computer account might be missing, or that the trust between the computer and the domain has been lost. Error messages or entries in an event log indicate similar problems or suggest that passwords, trusts, secure channels, or relationships with the domain or a domain controller have failed. A computer account is missing in Active Directory.

Chapter 8: WORKING WITH COMPUTER ACCOUNTS28 TROUBLESHOOTING COMPUTER ACCOUNTS: SOLUTIONS Reset the computer account in Active Directory. If the computer account is missing, create a computer account. If the computer still belongs to the domain, you must remove it from the domain by changing its membership to a workgroup. Rejoin the computer to the domain. Reset the computer account in Active Directory. If the computer account is missing, create a computer account. If the computer still belongs to the domain, you must remove it from the domain by changing its membership to a workgroup. Rejoin the computer to the domain.

Chapter 8: WORKING WITH COMPUTER ACCOUNTS29 SUMMARY A computer object represents a specific system on the network. To add a computer to a domain, you must create a computer object for it in Active Directory and then join the physical computer to the object. To create computer objects, you can use the Active Directory Users and Computers console, the Dsadd utility, or the Netdom utility. A computer object represents a specific system on the network. To add a computer to a domain, you must create a computer object for it in Active Directory and then join the physical computer to the object. To create computer objects, you can use the Active Directory Users and Computers console, the Dsadd utility, or the Netdom utility.

Chapter 8: WORKING WITH COMPUTER ACCOUNTS30 SUMMARY (continued) Computer objects for non–domain controllers are placed in the Computers container by default. Computer object have a SID that Active Directory uses to reference the computer in its group memberships and other permissions. The typical steps for troubleshooting a computer object problem include creating or resetting the object, removing the computer from the domain, and rejoining it to the domain. Computer objects for non–domain controllers are placed in the Computers container by default. Computer object have a SID that Active Directory uses to reference the computer in its group memberships and other permissions. The typical steps for troubleshooting a computer object problem include creating or resetting the object, removing the computer from the domain, and rejoining it to the domain.