Ethernet bridges were first developed in the early 1980s as data communications devices that link users of similar Ethernet networks. In recent years, standards (IEEE 802.3) were established by IEEE (Institute of Electrical and Electronics Engineers) that enabled Ethernet bridge technology to link users of dissimilar types of networks. Ethernet bridges map Ethernet addresses on each network segment, allowing only the necessary data traffic to pass through the bridge.

Typical computer data networks using Ethernet bridges include:

1. LAN (local area network), which connects information devices over a short distance through Ethernet bridges, such as in a networked office building, and is typically controlled by one person or organization
2. LAN-to-WAN (wide area network), which connects a geographically diverse collection of LANs, typically via an Internet service provider
3. MAN (metropolitan area network), which connects computer data networks spanning an area larger than an LAN but smaller than a WAN, such as a city
4. SAN (storage area network), which connects data servers to data storage devices, typically via fiber optic channel Ethernet bridges
5. SCADA (supervising control and data acquisition) network, which connects machinery controlling a business process such as manufacturing

The functions of Ethernet bridges include:

1. Controlling network data flow by receiving, forwarding and blocking data transmission to and from specific host sources
2. Isolating data transmission errors and collisions
3. Linking data traffic between different network protocols like TCP/IP, DECnet, AppleTalk, XNS and more
4. Segmenting a LAN into smaller, more manageable networks

Types of Ethernet bridges include:

1. LAN Bridges, which are modes of using Ethernet bridges for computer networking by connecting two or more LANs, even those running on different LAN types such as Ethernet and Token Ring
2. Ethernet to Wireless Bridges, which connect LANs and/or multiple device types, such as game consoles, printers and PCs, to a twisted-pair cable network via PoE (Power over Ethernet) converters
3. Remote Ethernet Bridges, which connect multi-LANs over telecommunications lines

Types of Ethernet bridge data speed rates include:

1. 10Base-T Ethernet at a rate of 10 Mbps (megabits per second)
2. Fast Ethernet at a typical rate of 100 Mbps
3. Gigabit Internet at typical rates of 1000 Mbps and 10,000 Mbps

Action Steps
The best contacts and resources to help you get it done

Start by reading the basics about Ethernet and Ethernet bridges

Get an overview of types of wired, cabled and wireless Ethernet bridges.

I recommend: Networking and communications technology giant Cisco Systems offers an easy to understand in-depth explanation of Ethernet and Cisco Systems Ethernet bridges. Wi-Fi Planet has a concise tutorial on using Ethernet bridges for computer networking, particularly wireless LAN. For more technically-oriented users, visit the IEEE website for primary information on 802.1 standards for LAN, MAN and WAN architecture and IEEE 802.3 standards for Ethernet-based LANs.

Explore the features of fiber optic Ethernet bridges

Learn how fiber optic and Fibre Channel (a mix of fiber optic and copper cabling) Ethernet bridges serve data storage area networks for business.

I recommend: IBM SAN Survival Guide explains in detail how Fibre Channel Ethernet bridges (Chapter 2: SAN fabric components) serve business data storage networks. Cisco Systems also offers understandable information on Fibre Channel over Ethernet. JumboSwitch, an Ethernet bridge product that's compatible with fiber optic or copper cabling, has a white paper (PDF) on the workings of Ethernet bridges. TC Communications offers its own fiber optic Ethernet bridge products.

Learn how using wireless Ethernet bridges serves LAN computers and other devices

Using wireless Ethernet bridges includes types like point-to-point wireless and multipoint wireless.

I recommend: Motorola has its PTP (point-to-point) series of wireless Ethernet bridges serving computer networking along with multimedia devices such as IP gaming and VoIP (Voice over Internet Protocol). Communication technology developer Asante sells its FM2008/9 series of 10/100BasicTX Ethernet switches for wireless workgroup networks. Digital communications developer D-Link offers a variety of wireless Ethernet bridge products such as the D-Link Xtreme N Duo Wireless Bridge/Access Point, which connects wireless networks, as well as gaming devices and DVRs.

Learn about cable-connected Ethernet bridge equipment

Power over Ethernet (PoE) is a mode of transferring data communications via networking Ethernet bridge equipment over copper Ethernet cable.

I recommend: Read an understandable explanation of PoE from Cisco Systems, check out their Catalyst line of PoE Ethernet bridges or switches, or learn about Cisco Systems’ Enhanced Power over Ethernet. D-Link also offers Power over Ethernet switch products, as does Asante. D-Link Ethernet bridge (or switch) products also serve their router products.

Learn about higher-speed Ethernet bridges

Gigabit and 10 Gigabit are two types of higher-speed Ethernet bridges.

I recommend: Read an understandable overview of Gigabit Ethernet technology from Cisco Systems. Leading networking product developer Netgear sells its ProSafe GSM series of Gigabit Ethernet bridges at data delivery speeds that include 10, 100 and 1000 megabits per second (Mbps). Intel sells its line of gigabit Ethernet bridge multi-port adapters.

Learn about Ethernet bridges for AppleTalk Macintosh computer-enabled networks

Ethernet bridges for AppleTalk (sometimes known as Apple LocalTalk Bridge) also serve Apple LaserWriter printer networks.

I recommend: Microsoft offers an understandable overview of AppleTalk networking and routing. At the Apple website, read about Apple LocalTalk and Apple LaserWriter Ethernet bridge products. Asante sells its AsanteTalk line of Ethernet bridges for AppleTalk, or you can buy AppleTalk Ethernet bridges directly from Apple.

Find Ethernet bridge suppliers and services

Locate consultants specializing in Ethernet bridges and other networking modes.

I recommend: Geek Squad, a leading nationwide computer consultant service, offers its Premium Wireless Networking services including setup of Ethernet bridges. For Dell Computer clients, the company has its Dell Network Assessment Service.

Tips & Tactics

Helpful advice for making the most of this Guide

• •  Ethernet bridges are sometimes also known as Ethernet switches or Ethernet adapters.
• •  Wireless Ethernet bridges are sometimes also known as wireless access points (WAP).