JSI Tip 0846. Your PDC and Master Browser should not be multihomed.

The Browser service does not merge networks. Each Browser is bound to one NIC and operates independently.Thus, a Master Browser that exchanges information with the PDC will not know about a server discovered on a different interface.

The UnboundBindings value introduced in NT 4.0 is a type REG_MULTI_SZ value designed to prevent the PDC from gathering browse lists on more than one interface but it does not force the Master Browser to only use the unbound interface cards. The entry is at:

HKEY_LOCAL_MACHINESYSTEMCurrentControlSetServicesBrowserParameters

and each line is set to an interface you wish to disable. Each line takes the form of:

NetBT_ and can be located by scanning HKEY_LOCAL_MACHINESystemCurrentControlSetServices.

You can off-load many services from the PDC to multihomed servers to increase their reliability.

Other symptoms of multihoming in Windows NT are:

NetBIOS does not have a problem with multihomed environments. An exceptionto this is with the NetBEUI protocol. If this protocol is used, and if thetwo interfaces are directly connected to the same physical segment, orindirectly connected through an intermediate system such as a bridge,NetBEUI must be unbound from one of the network interfaces. All of theother protocols that support NetBIOS do not have this problem. For TCP/IP,NetBIOS binds to the primary IP address bound to each network interfacecard (NIC). WINS can only bind to one NIC. By default, this is the first bound NIC inthe system. The network administrator must be aware of the bindings andonly assign the TCP/IP address for the NIC that is bound to WINS on all ofthe WINS clients. In addition, all WINS PUSH and PULL replication partnersmust be configured through this bound interface. To be certain of theinterface used, in the WINS Administrator, specify the remote WINS serverby its IP address. It is possible for a packet generated by WINS to useeither interface. This behavior is due to the local route table on the WINSserver. DHCP does not have a problem with multihomed servers. It binds to all NICs,and the service issues the correct scopes. Like NetBIOS, DHCP binds to theprimary IP address bound to each NIC.