The term bypass router might sound a bit confusing, right?
The purpose of this article is to help you understand the concept of bypass routers and master the basic setup methods.
1. What is a Bypass Router?
A bypass router, also known as a one-armed router, is a concept initiated by the hero Yang Guo (just kidding). Bypass routers are typically handled by routers with relatively strong CPU performance. Their main responsibility is to assist other devices in the network in obtaining data from foreign websites.
2. Wiring and Working Principle of Bypass Routers
The most basic and conventional wiring method for a bypass router is as follows:
Basic wiring method for bypass routers
Isn’t it a bit challenging to common sense? The LAN port of the main router actually connects to the LAN port of the bypass router? Yes, I did not make a mistake!
The main router can be an ordinary wireless router. All connected devices need to connect to the main router.
How does network data flow in this setup?
Data flow when accessing domestic websites
Data flow when accessing foreign websites
The above diagram basically demonstrates the role of the bypass router:
1. Analyze data packets to determine if encryption is needed;
2. Encrypt and decrypt data packets.
3. Setting Up a Bypass Router under OpenWrt
Assuming the IP address of the main router is 192.168.1.1, please adjust according to your actual situation!
1. Connect the LAN of the bypass router to the computer’s network port. No computer? Does the bypass router not support wireless? Try this: use an additional wireless router connected to the bypass router, then connect devices like mobile phones to the wireless router to set up the bypass router:
Setup method when the bypass router does not support wireless
2. Enter the management interface of the bypass router. We need to modify the LAN interface settings of OpenWrt.
[Network] – [Interfaces] – [Edit LAN]
In [Physical Settings], uncheck the [Bridge Interfaces] option, then select your LAN hardware interface.
After setting, remember to click [Save]. Here’s the key point, do not click [Save & Apply]! Do not click [Save & Apply]! Do not click [Save & Apply]! Do not click [Save & Apply]! Do not click [Save & Apply]! Do not click [Save & Apply]! Do not click [Save & Apply]! Do not click [Save & Apply]! Do not click [Save & Apply]!
Next, we also need to modify the firewall settings of the bypass router.
Go to [Network] – [Firewall] – [Custom Rules], and add the following code at the end:
iptables -t nat -I POSTROUTING -j MASQUERADEThen click [Restart Firewall]
In the firewall, add custom rules
Thus, the bypass router part of the setup is complete.
Now we need to save the settings.
In the upper right corner of the webpage, there is [Unsaved Settings], click it.
[Unsaved Settings] button
Click [Save & Apply] to save the modifications.
On the [Unsaved Settings] page, click [Save & Apply]
Thus, the setup of the bypass router is concluded.
3. Connect your computer (or mobile phone) to the LAN port or wireless signal of the main router. Enter the management interface of the main router.
4. Disable the DHCP service of the main router.
DHCP settings for TP-LINK/Mercury/Fast
DHCP settings for ASUS/Merlin
DHCP settings for OpenWrt main router
5. Setup is complete.
4. Wiring and Reconnecting Network Devices
Connect the main router and bypass router using a network cable.
Basic wiring method for bypass routers
After the wiring is done, please make sure to disconnect the network device connected to the main router before reconnecting the network to the main router. This is essential for fully implementing the bypass router setup.
5. Some Questions
Q: In what situations is it recommended to use a bypass router?
A: Generally, the following situations are present:
1) Do not want to change the network structure, or cannot change it
2) The main router has some functions that the bypass router cannot achieve, such as flow control
3) Just want to set up a bypass router, no reason needed
Q: I have a fiber modem dialing, followed directly by AC and AP, without the main router shown in the diagram. But I also want to use a bypass router. What should I do?
A: Just imagine the fiber modem as the main router.
Q: I am using R1/R1S, and the LAN interface speed is not as high as the WAN interface. Can I use the WAN interface when setting up a bypass router?
A: Yes, you can. You can refer to another article (not written yet) for details.
Q: Many people in the comments say they failed to set up according to your tutorial. Can it work?
A: After a thorough check, I found that I missed a step in the diagram, which is after canceling the bridge for LAN, you must select the physical interface of LAN in the interface settings. Most people get stuck at this step. Please pay attention!