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:


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

NetBT_<NIC driver name that ends in a number> and can be located by scanning HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services.

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 exception
to this is with the NetBEUI protocol. If this protocol is used, and if the
two interfaces are directly connected to the same physical segment, or
indirectly connected through an intermediate system such as a bridge,
NetBEUI must be unbound from one of the network interfaces. All of the
other protocols that support NetBIOS do not have this problem. For TCP/IP,
NetBIOS binds to the primary IP address bound to each network interface
card (NIC).
WINS can only bind to one NIC. By default, this is the first bound NIC in
the system. The network administrator must be aware of the bindings and
only assign the TCP/IP address for the NIC that is bound to WINS on all of
the WINS clients. In addition, all WINS PUSH and PULL replication partners
must be configured through this bound interface. To be certain of the
interface used, in the WINS Administrator, specify the remote WINS server
by its IP address. It is possible for a packet generated by WINS to use
either interface. This behavior is due to the local route table on the WINS
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 the
primary IP address bound to each NIC.

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