How to change the IP of the Mercury router's LAN port? I clashed with the optical modem segment, so I switched from 192.168.0.1 to 2.1 during the entire process

first explain why I set this up: My optical modem is a telecom combo, with the backend address 192.168.1.1; the Mercury router D191G is installed under the modem, and my own background is 192.168.0.1. Normally, we wouldn't interfere with each other's business, until one day I moved the router to a low-voltage box and casually switched the optical modem from bridge back to router mode. That night, the house started running out of control—the TV box buffered every ten minutes, my phone would freeze for a whole time while watching videos via WiFi, and Mi Home devices would disconnect in batches late at night. After checking all night, I found that after the optical modem changed to retrace routing mode, DHCP occasionally assigned the 192.168.1.x address to devices that should be in the 192.168.0.x subnet, causing conflicts between the two sides.

solution is simple: change Mercury's LAN IP to a completely different network segment from the optical modem, with each company managing its own . This setting isn't very well hidden, but there were a few pitfalls when I changed it. I've stepped through them step by step and am writing them for everyone.

first clarify: what is a LAN port IP and when should you change it

There are actually two types of addresses on routers, which are especially easy for beginners to confuse. One is the WAN port address, which is assigned to the router by the optical modem. Your home internet access depends entirely on it, so you don't need to worry about it; The other is the LAN IP, also known as the router's management address or gateway address. After all your devices connect to WiFi, the gateway refers to it. Mercury's default is 192.168.0.1. Enter it in the address bar to access the Mercury backend.

three situations where you need to change the LAN IP:

the first is network segment and the is affected. Like me, the upper-level optical modem is 192.168.1.1. If your Mercury has been modified and it's also 192.168.1.1, two devices on the same network are stacked together, and the packet doesn't know whose to listen to, resulting in intermittent intermittent performance—some devices can access the internet, some can't. This is the most common and the most important thing to change.

the second option, connected to the second router . For example, if you convert an old Mercury as an AP, or use two Mercury cascades with both 192.168.0.1 addresses identical, the mess up. You need to change one to 192.168.2.1 or another segment.

the third type: company VPN or remote work software conflicts . Some organizations only use the 192.168.0.x segment for their internal network. If you connect to a VPN at home and your own network overlaps with your company, the VPN drops every day. Replace your home router with a less popular 192.168.5.1 segment, and it instantly becomes quiet. My colleague has this problem. The network at home is exactly the same as the company's monitoring segment, and after changing the VPN, it's much more stable.

Hands-on Modification: Five-step operation in the Mercury backend

I demonstrated with the D191G; other models are pretty much the same. Step 1: Connect Mercury WiFi to your phone or computer (or plug the network cable into a LAN), enter 192.168.0.1 in the browser's address bar, and enter the management password to enter the backend. Note: the address bar is not the search box; if you enter it incorrectly, search engines will redirect you.

Step two, go to the backend and find "Routing Settings" or "Advanced Settings." Inside there is a "LAN Port Settings," and some firmware versions are called "LAN IP." When you click in, there is an IP address input box, currently 192.168.0.1.

step three: decide what to change before . This isn't just a random entry—three rules: Don't use the same range as your upper-level optical modem (if your modem is 192.168.1.1, don't use 192.168.1.x); don't use 192.168.31.x (Xiaomi router's chassis, as connecting Xiaomi devices in the future can cause collisions); and recommend simple and niche options like 192.168.2.1 or 192.168.5.1. I changed it to 192.168.2.1.

step four, after making changes, click Save. The router will automatically restart and resume after a few dozen seconds. Step 5 is the most important: after restarting, you will find that you can no longer access 192.168.0.1. Don't panic, this is a normal — the router has been moved, and the new address is 192.168.2.1. Disconnect your phone's WiFi and reconnect once, enter a new IP in the address bar, and use the original management password to access the backend.

the entire operation lasts five minutes. But eight out of ten beginners get stuck at step five, thinking the router has been damaged, but it's actually just the house number changed.

two things you must do after making changes: check the DHCP and connected device

LAN IP addresses. Once the IP address changes, the DHCP sub-address range will automatically change (from 192.168.0.x to 192.168.2.x). Generally, you don't need to do this manually, but you need to check the "DHCP Server" page to confirm: the address pool starts at 192.168.2.100. When closing 192.168.2.199 or similar, the gateway column shows the new IP. If a device still holds onto the old address, it means it caches the old gateway. turn off that device's WiFi and then turn it on, or simply restart it to get the new address.

the night I changed it, the TV box just wouldn't change its address, and only after restarting the box did it return to normal. Families with many smart devices should be mentally prepared: for 2.4G devices like cameras and speakers, switching the network segment means they get to know the router anew. Most of them switch to the router themselves, while some older devices need to be powered off and restarted.

After modifying, you can't connect to the backend. How do you fix yourself

If your WiFi disconnects halfway through and you can't access the backend again, here are two tricks.

first trick: check the mobile gateway . Connect your phone to Mercury WiFi and log in to WLAN. For details, check the IP shown in the 'Gateway' or 'Router' section—that's Mercury's current address. Just enter it and you'll get in. For computers, ipconfig check the default gateway, and the same applies here. This is the most lossless method, because the purpose of changing the LAN port is to change the segment. Once the device is connected, the gateway will automatically display the new address.

second trick, if you really can't find it (for example, change a segment you even forgot), hold down Reset for seven or eight seconds to restore factory , then go back to 192.168.0.1 and try again. Remember your broadband account password before resetting. After changing it, you need to dial again. I previously wrote an article specifically about how to reset internet after resetting. If you need it, check my homepage.

who doesn't need to go through all this trouble

to be fair, most families don't need to change this. With the standard connection of optical modem bridging and router dialing, the modem and router are not in the same segment and each is doing their own thing. If your network is working fine and you just want to change it, I advise you to take a break—changing this setting won't yield any profit, and there's the risk of disconnection.

However, the following situations are worth fixing: intermittent home device checks for network segment conflicts; Connect to the second router; The VPN overlapped with the company intranet. Take it for granted before taking action.

It's been over two months since I changed it, and there hasn't been any address disputes again. The whole experience gave me one thing: encounter these intermittent and mysterious faults, first check if the two "housekeepers" at home are competing for the same house number. Switching the network segment takes five minutes, which is easier than replacing routers or reporting broadband repairs.