Differences Between Bridge Mode and PPPoE Mode

Welcome to the Network Engineer training tutorials by CoreNetworkZ Tech Solutions. Today, I will explain the difference between configuring a broadband modem in bridge and PPPoE modes.

I received multiple questions (from my readers) asking about the differences and benefits of configuring an ISP modem in PPPoE mode vs Bridge mode. So, I am writing this detailed article to answer all those questions.

In this section, I will answer a repeated question from my readers about what PPPoE and Bridge configurations are.

Regular readers of CoreNetworkZ Tech Solutions know I worked as an apprentice for an ISP during my B.Tech days.

The first lesson I learned was to set up a home LAN with their ISP devices. During this period, they trained me to configure a DSL modem in bridge and PPPoE modes.

So, now you understand how I learned to set up a broadband modem in PPPoE and bridge modes. Now, let me answer one question from Julia.

She is a regular reader and very active in our tech community.

She wanted to know the practical difference between PPPoE and Bridge modems. She also wanted to learn how to recognize a PPPoE modem.

Julia asked this question in the comment section, and I will answer it in this section.

If you configure the modem in bridge mode, you need a dialer to connect to the Internet. The dialer will ask you to enter the ISP-provided username and password.

If your modem is in PPPoE mode, the connection is always on. What does it mean? It means you do not need a dialer to access the Internet.

I explained one practical difference, but that is not all. Let me compare the key differences between a modem in bridge mode and a modem in PPPoE Passthrough mode. In this section, I will teach you six key differences.

1. Number of Supporting Devices

   Let me explain the first difference. The primary difference is the number of supported devices. Bridge Mode Supports only one computer, but PPPoE supports multiple computers.

2. ON or OFF State

   I explained this point before. In bridge mode, you need to dial every time to go online. PPPoE mode is always connected.

3. Cyber security

   PPPoE is more secure than bridge mode. So, why is that? The reason is simple. The modem firewall will not work in bridge mode.

4. Port Forwarding

   In Bridge mode, there is no need for port forwarding. In PPPoE mode, you may need port forwarding. This point is helpful for online gamers. Arun Gopi, one online gamer, complained about port blocking.

   He asked my advice.

   So, my advice to online gamers is to choose a bridged modem.

5. Support for NAT

   Let me explain the 5^th difference between PPPoE and Bridge mode. It is about the NAT feature on an ISP modem. So, do you know which mode of modem configuration supports the NAT feature?

   PPPoE mode supports NAT.

   There is no NAT in bridge mode. Samantha Turner asked why bridge mode does not support the NAT feature.

   Samantha is a Computer Science student.

   The answer is simple. By bridging, the modem passes the connection directly from the ISP to the computer/router. So, it cannot support the NAT feature.

   NAT = Network Address Translation

   I believe I have answered her question.

6. The Supported IP Addresses

   Let us recall the question from Julia. She asked how to recognize if the modem is in PPPoE mode.

   We can find it easily. All we need to do is check the IP address modem assigned to the connected PC.

   The computer connected to the modem in bridge mode gets the public IP address. Your computers get private IP addresses in PPPoE mode. So, you have learned the 6th difference between a bridge and a PPPoE modem.

I have explained the six key differences between PPPoE and Bridge mode. Now, let me answer a few questions asked by readers.

Max Cassidy asked me if a bridged modem supports the DHCP. The answer is no. Only a modem configured in PPPoE supports the DHCP.

I feel I must mention the comment by Laxmi Rao. She shared her experience with a faster Internet connection on a bridged modem. I support her view because a bridged modem does not waste time on features like NAT and DHCP.

Now, I am concluding this article. Today, you learned the differences between PPPoE and Bridge mode. If you wish to further studies, I suggest you visit the following links under the reference headline.

1. https://www.cisco.com/c/en/us/td/docs/optical/15000r4_5/ethernet/454/guide/ios4145/45bridg.pdf
2. https://www.juniper.net/documentation/us/en/software/junos/multicast-l2/topics/topic-map/bridging-and-vlans.html
3. https://www.systosys.com/viewtopic.php?t=14
4. https://community.cisco.com/t5/routing/configure-two-routers-in-bridge-mode/td-p/1189709