What happens when a domain controller that holds a FSMO role fails and will not returned to the network?

yes and it is recommended that the roles should be seized and transferred to a healthy DC

They way to transfer is as follows

1. On any domain controller, click Start, click Run, type Ntdsutil in the Open box, and then click OK.

C:\Windows>ntdsutil

ntdsutil:

1. Type roles, and then press ENTER.

ntdsutil: roles

fsmo maintenance:

Note: To see a list of available commands at any of the prompts in the Ntdsutil tool, type ?, and then press ENTER.

1. Type connections, and then press ENTER.

fsmo maintenance: connections

server connections:

1. Type connect to server <servername>, where <servername> is the name of the server you want to use, and then press ENTER.

server connections: connect to server server100

Binding to server100 ...

Connected to server100 using credentials of locally logged on user.

server connections:

1. At the server connections: prompt, type q, and then press ENTER again.

server connections: q

fsmo maintenance:

1. Type seize <role>, where <role> is the role you want to seize. For example, to seize the RID Master role, you would type seize rid master:

Options are:

Seize domain naming master

Seize infrastructure master

Seize PDC

Seize RID master

Seize schema master

1. You will receive a warning window asking if you want to perform the seize. Click on Yes.

fsmo maintenance: Seize infrastructure master

Attempting safe transfer of infrastructure FSMO before seizure.

ldap_modify_sW error 0x34(52 (Unavailable).

Ldap extended error message is 000020AF: SvcErr: DSID-03210300, problem 5002 (UNAVAILABLE)

, data 1722

Win32 error returned is 0x20af(The requested FSMO operation failed. The current FSMO holde

r could not be contacted.)

)

Depending on the error code this may indicate a connection,

ldap, or role transfer error.

Transfer of infrastructure FSMO failed, proceeding with seizure ...

Server "server100" knows about 5 roles

Schema - CN=NTDS Settings,CN=SERVER200,CN=Servers,CN=Default-First-Site-Name,CN=Sites,CN=Configuration,DC=dpetri,DC=net

Domain - CN=NTDS Settings,CN=SERVER100,CN=Servers,CN=Default-First-Site-Name,CN=Sites,CN=Configuration,DC=dpetri,DC=net

PDC - CN=NTDS Settings,CN=SERVER100,CN=Servers,CN=Default-First-Site-Name,CN=Sites,CN=Configuration,DC=dpetri,DC=net

RID - CN=NTDS Settings,CN=SERVER200,CN=Servers,CN=Default-First-Site-Name,CN=Sites,CN=Configuration,DC=dpetri,DC=net

Infrastructure - CN=NTDS Settings,CN=SERVER100,CN=Servers,CN=Default-First-Site-Name,CN=Sites,CN=Configuration,DC=dpetri,DC=net

fsmo maintenance:

Note: All five roles need to be in the forest. If the first domain controller is out of the forest then seize all roles. Determine which roles are to be on which remaining domain controllers so that all five roles are not on only one server.

1. Repeat steps 6 and 7 until you've seized all the required FSMO roles.

2. After you seize or transfer the roles, type q, and then press ENTER until you quit the Ntdsutil tool.

Note: Do not put the Infrastructure Master (IM) role on the same domain controller as the Global Catalog server. If the Infrastructure Master runs on a GC server it will stop updating object information because it does not contain any references to objects that it does not hold. This is because a GC server holds a partial replica of every object in the forest