192.168.1.1 Will changing the network segment cause the network at home to crash? Calculate these five accounts before taking action

Last month, I helped my neighbor change his router. As soon as I walked in, I saw that he had followed the tutorial on his mobile phone and had changed the LAN port of the new router from 192.168.1.1 changed to 192.168.2.1 . After the modification, there were no bricks, but his Synology couldn't connect, the wireless printer disappeared, and two old cameras went offline all night. He thought the router was broken and almost ordered another one.

I later helped him retrieve the settings one by one, and the problem lay in: The tutorial only teaches "how to make changes", but not "what accounts to calculate before making changes". In this article, I will go through the pitfalls this time and write it to those who are ready to move. 192.168.1.1 people. If you don't plan to change it, you can save it first and look it up again when you really encounter the same network segment as optical modem.

First distinguish: What you modified is the backdoor of the router, not the broadband port.

There are actually two types of addresses on the router, and it is especially easy for novices to get confused. One is the WAN port address, which is assigned by the optical modem or the operator and is responsible for external access to the Internet. You don't need to worry about it at ordinary times. ； The other type is the LAN port IP, also called the management address and gateway address. You enter it into the browser. 192.168.1.1 When you enter the backstage, you enter through this door. It is also the gateway you get after the device is connected to WiFi.

When I said "change the network segment", what I changed was the IP of the LAN port at the back. After changing the broadband account, dial-up password, and the optical modem end, everything will not be affected, and your broadband package will not change. Many people panic when they hear that the network segment has been changed, thinking that they need to change their broadband settings, but in fact they don't. At most, it is equivalent to moving the house numbers of all the equipment in the house from building 1 to building 2. After the move, everyone has to re-recognize the road, but the optical fiber outside is still the same.

It’s easy to tell whether you’ve made the right changes: you lose 192.168.1.1 If you can go in and see WiFi, DHCP, and device management, that is the door of the router. ； When you go in, you will see broadband, voice, and IPTV. That is the door of optical modem. If you can't tell the difference between the two sides, Is it an optical modem or a router? It's written very carefully.

These three situations really need to be changed, so don’t be itchy.

I don’t recommend changing the network segment “for security reasons” because 192.168.1.1 There is no danger in itself, but if you correct it, it will cause a lot of trouble. I have encountered three types of things that really need to be done:

• Both optical modems and routers 192.168.1.1 , the login page jumps randomly. The most typical example of this is that the optical modem delivers addresses, and the router's own backdoor also occupies 1.1, causing a fight between the two sides. If you want to fix it once and for all, change the router to another segment.
• There is a second router or AP connected to the home, and the two backdoors have the same IP address. Fill in both the main router and the old route 192.168.1.1 , change one of them, so that each can take care of his own business.
• The company's VPN and remote office network segments crashed. The internal network of the work is 192.168.1.x, and I also use 1.x at home, but the connection to VPN is disconnected. Changing your home to a less popular area can avoid this pitfall.

If your home only has a single router connected to the modem and the login is normal, then don't touch it. Changing the network segment is not a physical examination item. If there is nothing wrong, you don’t need to do it.

Which paragraph should I change to? Three principles, don’t fill them in randomly

Tutorials often just say "Change to 192.168.2.1 」, but it doesn't say that you can also change it to something else. I usually choose from three options: Don’t be on the same segment as Optical Mode, don’t be on the same segment as the second device at home, and try to avoid Xiaomi’s 192.168.31.x. It will not be easy to misunderstand when connecting Xiaomi devices in the future. The following three are what I commonly use:

The last digit can theoretically be filled in from 1 to 254, but do not use 0 and 255, let alone fill in the commonly used segment of the DHCP address pool, to avoid fighting with dynamically allocated addresses. If you want to be on the safe side, choose 2.1, and wait until you are familiar with it before playing with the less popular segments.

There is one thing I would like to mention specifically: Don’t see 31.1 written on Xiaomi’s backend, so just change your general router to 31.1. The 31 segment is where Xiaomi devices are used to staying. After you change it, if you connect a Xiaomi to do Mesh or AP in the future, it may automatically bump into your hand, which is equivalent to laying a minefield for yourself. It's okay to want to differentiate between brands, but staggering network segments is much more important than imitating a certain brand.

The entrance to changing the LAN port IP is different for each brand, so there is no need to memorize them all. The old interface of TP-Link is in "Network Parameters → LAN Port Settings", the old models of Mercury and Tenda follow the path of TP, Xiaomi is in "Common Settings → LAN Settings", and ASUS is in "Internal Network → LAN IP". If you can't find the entrance, just look at the words "Network Settings" and "Advanced Settings". I have helped people change five or six brands, and they are basically hidden under these two layers.

Before you start, cut out these three pages of the old backend.

Before changing the network segment, I flipped through the pages of my neighbor’s old backend and asked him to take pictures of three things with his mobile phone.:

• WiFi settings page: Dual frequency name, password, encryption method. Although changing the network segment will not clear them, if you accidentally restore the factory during operation, this is the only basis for you to quickly restore.
• DHCP settings page: Where did the address pool come from? Has the IP been fixed for the device? After changing the new address, if the rules of the fixed IP are not changed accordingly, the devices will lose contact collectively.
• Port forwarding and DMZ page: Everything filled in is the 192.168.1.x intranet address. After changing to 2.x, these rules still point to the old address, and NAS external network access and monitoring review will be interrupted.

The neighbor’s house only took pictures of the WiFi page and left out the last two pages. As a result, the Synology port forwarding point was still 192.168.1.50 This address has disappeared. Later, I wrote about the pitfalls of static IP binding in an article. 192.168.1.1 Bind a static IP to the device The logic is the same. You must write down the old address before changing the network segment.

Don’t be in a hurry to reset the three “false faults” that will appear after correcting them.

After changing the LAN port IP and restarting the router, most people will feel that the sky has fallen.: The background suddenly cannot be opened, the mobile phone is full and there is no network, and the smart devices are collectively offline. In fact, most of these three things are normal reactions after moving, and they are not broken.

The backend cannot be opened because no one lives at the old address. You need to go to the browser and enter the new address, for example 192.168.2.1 . The reason why the mobile phone has no internet connection is because it still holds the old gateway in its hand. 192.168.1.1 , the fastest way is to turn off WiFi and turn it on again, or "forget this network" and reconnect to let it get the new address of 192.168.2.x. 2.4G equipment such as old cameras and printers generally need to be powered off and restarted before they can recognize the new network segment again.

Commands can also be verified. On a Windows computer, press Win+R to enter cmd, first type ipconfig /release Knock again ipconfig /renew , see if the default gateway has changed to a new address. Just look at the "Gateway" column in the WiFi details on your mobile phone, which is much faster than guessing. I can't figure out how to arrange the grid if there is no network. WiFi is full but cannot access the Internet. This article The ideas can be used continuously.

The neighbor's most troublesome thing that night was the Synology DS920+, because port forwarding also pointed to 192.168.1.50 , there is no such machine in the new network segment, and all external access will naturally time out. Later, I logged into the router and changed each old IP in the forwarding rules to 192.168.2.50 , and fixed Synology back to the new address, and the external network was restored. The printer also had the same problem. The Brother printer usually relied on the router to fix its IP address. After changing the segment, it couldn't get the address. Finally, it returned to the list after the power was turned off and on again. So don’t just focus on whether your mobile phone can access the Internet. First, take a look at these devices that usually don’t make a sound.

After writing this, it will be much clearer when I spread out the five accounts.: The first is which segment the optical modem is on, the second is whether there is a second router in the same segment at home, the third is the network segment recommended by the company's VPN, the fourth is the device address fixed by DHCP, and the fifth is the old IP written in the port forwarding and DMZ. Take a look at these five items, and then decide whether to change it or not, and which section to change it to. Don’t panic after you actually take action. Follow the following steps for self-rescue after losing contact.

Lost contact and self-rescue: Remember the three ways, and touch the reset hole last.

Even after changing it, you can't even enter the new address. Follow the following sequence. Most of them don't need to be restored to factory settings.

• Look at the gateway: Connect your mobile phone to the router WiFi, enter the details and look at the IP displayed in "Router/Gateway". That is where it really lives now, enter it directly.
• Use network cable: Plug the computer into the router LAN port, change the network card to "obtain IP automatically", and then type ping 192.168.2.1 . If it works, change the browser or clear the cache. ； If it doesn't work, first check whether the network card is 192.168.2.x.
• Manually set IP: I really can’t get the address, so I manually set the computer’s IPv4 to 192.168.2.10 , subnet mask 255.255.255.0 , gateway 192.168.2.1 , then enter the background.

If you still can't get in after trying these three, consider resetting. But reset will clear all broadband dial-up, WiFi, and port forwarding. Redial after factory reset There is a set sequence, if you can't go, don't go. Changing the network segment is, in the final analysis, "ten minutes to settle accounts beforehand and two hours to collect equipment afterwards." If I really want to take action, I should first take a look at the optical mode section, VPN section, and DHCP fixed items, and then it is not too late to change them.