Local Network Bridge

The Local Network Bridge component contains a network bridge driver that transparently connects two or more network segments so that hosts on those segments identify the resulting internetwork as one network segment. This helps set up small multisegment networks where easy configuration is more important than scalability.

When using Internet Protocol (IP) on a bridged internetwork, the internetwork is treated as a single IP subnet, eliminating the need to configure IP routing.

This component supports any network interface that is an Ethernet media type and uses standard Ethernet framing. In addition, it supports IP over 1394 segments with the Microsoft IP1394 driver.

It implements the spanning tree algorithm as described in IEEE 802.1D-1990. When hardware permits, the spanning tree algorithm functions as a Media Access Control (MAC) bridge as described in the specification. When the network bridge operates over hardware that does not support gratuitous send and receive operations, such as many wireless adapters, it only supports IP and uses Address Resolution Protocol (ARP) to transparently connect network segments.


There are no services associated with this component.

Associated Components

No other components interact with this component.


This component is implemented as a Network Driver Interface Specification (NDIS) intermediate network driver, thus functioning as both a network protocol and a network miniport, also known as a virtual adapter.

To operate correctly, this component must be bound to two or more network adapters. All components other than the network bridge should be unbound from bridged adapters. Protocols and services that the user wants to operate over the bridged segments should be bound to the virtual adapter exposed by the network bridge.

The tools that perform binding operations with the bridge also enable particular network protocols, such as TCP/IP, to be bound or unbound from particular network adapters.

Once bound, the network bridge requires no additional configuration.


The Home Networking Monitory Library component can be used to force the network bridge to operate in layer 3 mode for IP only. This is necessary for certain network adapters that incorrectly report that they support gratuitous send and receive messages.

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