In the previous articles, the term PPPoE was mentioned many times. Most people who have configured a broadband network will be familiar with this term. But what exactly is PPPoE and why we are using it?
What is PPPoE
To tell what is PPPoE (Point to Point Protocol over Ethernet), we must first understand PPP (Point to Point Protocol). PPP is a protocol that uses a telephone line to do real "dial-up" to accessing the Internet in the past. With this protocol, point-to-point communication between a PC and an ISP's equipment can be achieved on a telephone line that was originally for voice phone calls without adding extra lines. Later, with the development of the Internet, dedicated lines such as ADSL, and now optics fibre are developed to transmit IP packets of the Ethernet network directly. Physically, PPP was no longer needed. But in order to take advantage of the user authentication function included in PPP to charge for what they provided, the ISPs packed PPP into Ethernet frames, and PPP over Ethernet was born.
Then the question comes, just for authentication, and in 2019, the ancient telephone based protocol is still used. Isn't there any other authentication method?
With the birth of ipv6, the redesigned IPoE (IP over Ethernet) protocol based high-speed Ethernet connections has entered the stage. IPoE allows transmit IP packets on the Internet directly as what we did in a LAN network, eliminating the boilerplates to deal with PPP protocol and conversion steps.
In terms of authentication, IPoE authenticates user access through physical lines. After the line is completed, a fixed ipv6 network segment will be assigned and used for access. No username and password and corresponding auto-dial settings are required.
In addition to user authentication, IPv6-based IPoE has the following advantages over PPPoE based on telephone line connections of the last century:
Using PPPoE, users need to generate PPPoE frames containing authentication information on the router, and then the modem perform modulation and demodulation in accordance with the PPP protocol. On the ISP's side, each Ethernet frame needs to be disassembled, and the PPP authentication infos taken out of it must be sent to a special device for authentication. These steps that do not help the communication itself increase the communication delay and instability of the network. IPoE can achieve the same native IP communication as the local area network without introducing other special protocols, making the entire network more concise and stable.
Because of the point-to-point characteristics of PPP, the ISP's equipment (NTE) needs to maintain a connection session for each Internet user. With the increase of access users, this NTE device will become the bottleneck of the entire network, limiting the transmission speed. IPoE that directly transmits the IP protocol does not need to go through such a point-to-point connection, and the more recent IPoE device itself can provide a much higher throughput rate than in the PPPoE era, so the data transmission speed of the IPoE connection is much higher than that of the traditional PPPoE network.
I made a test on my own network that showed a clear difference between PPPoE and IPoE.
In the previous section we configured IPv4 pppoe connection, and I'll talk about IPv6 in this article. IPv6 connection s[…]