It is possible to have the OS to balance the network load for the computer when having several Network Adapters.
This is controlled by these DWORD values :
[HKEY_LOCAL_MACHINE \SYSTEM \CurrentControlSet \Services \NetBT \Parameters]
RandomAdapter = 1 (Disabled = 0, Enabled = 1, Default = 0)
SingleResponse = 1 (Send All = 0, Send One = 1, Default = 0)
The RandomAdapter specifies whether it should respond back with a random IP-Address (One for each adapter), or if it should respond back with the IP Address for the adapter the request was received from.
The SingleResponse says that it should only send one IP address when WINS does a name query request.
You can also manually configure the interface metrics to allow load balancing between multiple network adapters:
Install TCP/IP for all adapters and assign them a different IP-address on the same subnet (Becomes Multihoming)
If a certain adapter should be dedicated for outgoing traffic then it should be given a lower interface metric
If a certain adapter should be used for certain incomming traffic then make sure the clients connects to its IP-Address
Note Netbios traffic (outgoing/incoming) can only be handled by a single adapter or else a name conflict will arise (Though it doesn't have to be the one dedicated for outgoing IP traffic)
Note it is possible for clients to connect to a service (FTP/HTTP,etc.) through all network adapters (To force clients to use a certain adapter one can use DNS or port blocking)
To configure the metric in Win2k/WinXP (WinNT4/Win9x can use the command "route"):
Open Control Panel
Double click Network and Dial-up Connections(Win2k) or Network Connections(WinXP)
Righ click Local Area Connection and select Properties
Double click Internet Protocol (TCP/IP)
Press Advanced-button and it is possible to configure gateways and interface metric.