Bridges and routers both provide a means for consolidating individual networks into internetworks. They both provide a wide range of functionality while helping to simplify the task of connecting networks together. And both can be found at a reasonable cost. However, each technology has its own advantages and disadvantages. Here are factors to consider when choosing a bridging or routing solution.

1. Bridges are simple to install.
2. The presence of a bridge is transparent to users from the instant it is first installed, and bridges adapt automatically to network changes.
3. Bridges can connect networks running different protocols without requiring additional software. They operate below the network layer in the OSI model so that it is not necessary for network managers to know in advance which high-level protocols will be used.
4. Bridges form logically single networks, that is, all interconnected network segments have the same network address so computers can be moved easily within the bridged network.
5. Bridges can deliver a tremendous amount of performance at relatively modest prices.

1. Bridges cannot take simultaneous advantage of redundant paths in a network. That is, bridges cannot split a load over network segments.
2. Bridges can propagate significant increases in network traffic at certain times, flooding the network. This can occur when a packet with an unknown address is sent out.
3. Bridges cannot prevent "broadcast storms." A broadcast storm may occur when certain broadcast protocols cause packets to be flooded to every port. In the event of a malfunction or an incorrectly configured parameter, these activity spikes can be severe enough to render the entire network inoperable.
4. Bridges do not provide significant support for fault isolation or other distributed management capabilities. Networks become harder to manage and maintain as their size and complexity increase. Because bridges form a single logical network, fault isolation in very large bridged networks may become virtually impossible.
5. The use of bridges may prevent the use of certain applications over the network. This can occur when an application needs to use unique names on a network-wide basis. If two copies of the application are running, each under the same name, the application could malfunction and affect the performance of the whole network.

1. Routers are generally more flexible than bridges. They can differentiate between paths by means of factors such as cost, line speed, and line delay, and they can be configured for equal-cost load splitting. They can utilize all active paths.
2. Routers provide a protective fire wall between subnetworks. This protects against broadcast storms and prevents incidents that occur within one subnetwork from affecting others.
3. Router-based networks support any topology and can more easily accommodate extensive network growth and complexity.
4. Routers provide and can take advantage of redundant network paths, allowing them to load split certain applications to make the best use of available bandwidth.

1. Routers are more difficult to set up and configure. Because they are protocol-dependent devices, they require software for each protocol that they run and each individual protocol must be separately and correctly installed.
2. Routers make movement of end systems between network segments more difficult. Since each segment has a different network address, moving between segments requires that the network administrator assign a new network address to the relocated end system.
3. If the router is running a static routing protocol, configuring a router can be a laborious, time consuming process.
4. Some low-level protocols, like NetBIOS, cannot be routed. Such protocols are those that do not include a network layer, and accordingly must be bridged.