PPPoE and Connection Sharing

More of this Feature Part 1: PPPoE Technology Part 2: Benefits and Drawbacks of PPPoE

Join the Discussion "If it's an internal DSL modem using PPPoE, you'll be hard-pressed to find a working solution [for connection sharing]. The main reason DSL providers like these type of modems is that they're extremely difficult to share over a LAN, if at all." -TOEPOPPER

Related Resources DSL vs. Cable Modem Network Protocols

Elsewhere on the Web RFC 2516 - PPPoE

PPPoE supports a maximum MTU of 1492 bytes. Ethernet, however, typically supports a maximum of 1500 bytes, and many operating systems such as Windows set their default MTU to the larger value. 1500-byte packets sent over a PPPoE connection typically get lost. For the customer, this means their applications won't work and often their connection to the Internet will get dropped.

On older versions of Windows, you may need to adjust your network settings and lower its MTU. Its also possible to get ICS working with PPPoE with some additional effort [1]. Alternatively, several third-party "proxy" technologies have been developed that solve this and other technical problems with PPPoE. Many network professionals recommend replacing the connection software that service providers include with their broadband modems with one of these, if necessary:

• RASPPPOE
• WinPoET and MacPoET

Finally, most types of broadband routers now support PPPoE. Many network professionals recommend purchasing a broadband router to solve Internet connection sharing as well as security concerns pertaining to broadband access.

Conclusion

PPPoE is a technology that, ideally, a home networker would not need to know much about. However, a little knowledge of PPPoE goes a long way in avoiding some common pitfalls in home networking with broadband. If your service provider uses PPPoE, take extra care in setting up Internet connection sharing. Install one of the recommended software proxy packages for PPPoE, or consider purchasing a broadband router with PPPoE support -- just be aware that some models, particularly older models, do not support it.

Highly technical folks, those looking for maximum performance or to set up servers at home, may wish to avoid a PPPoE-based service. However, PPPoE services continue to grow in popularity and don't appear to be "going away" anytime soon.