Many users are familiar with the situation when a router suddenly stops allowing new devices onto the network or artificially reduces speed. Often, the problem lies not with a hardware failure, but with software restrictions that are set by default or were configured by the network administrator. Connection limitation It can manifest itself in different ways: from a complete ban on authorization to a reduction in channel bandwidth to a minimum.
In most cases, the cause is the settings DHCP servers, exhausted IP address pool or enabled feature MAC filteringProviders may also impose their own limits on the number of simultaneously connected devices, especially in mobile plans. Understanding the nature of the block is the first step to restoring full access.
Before attempting any complex repairs, it's important to rule out common causes, such as overheating equipment or a temporary ISP outage. However, if you're certain the problem lies with your local network's software settings, you'll need to access your router's configuration. The key point is access to the admin panel, without which further actions are impossible.
Diagnosing the reasons for blocking new devices
The first step is to determine at what level the cutoff is occurring. If new devices simply can't obtain an IP address, the problem is most likely in the address pool. DHCPThe router simply assigns the last available slot on the list, and when it runs out, connection becomes impossible. This is a common situation in offices or homes with a lot of smart technology.
Another common scenario is work MAC address filterIn this case, the router sees the device but deliberately denies it access, even if the password is entered correctly. You can verify this by attempting to connect a phone that previously worked on this network but was removed from the trusted list. It's also worth paying attention to the indicators on the router: a blinking WLAN indicator without establishing a connection often indicates an address conflict.
Don't forget about software limitations from your provider. Some telecom operators use technology DPI Or analyze traffic to detect internet sharing with other devices (tethering). In this case, speeds may drop to a minimum, or the connection may be disconnected immediately after data transfer begins.
⚠️ Please note: If you are using a corporate network or public Wi-Fi at a hotel, attempts to bypass restrictions may violate the terms of service and lead to a permanent ban of your account.
For accurate diagnosis, it is useful to use network scanning utilities such as Fing or WiFi AnalyzerThey will show how many devices are actually online and which IP addresses they are using. This will help you determine whether your connection limit has been reached or if the problem lies deeper.
Setting up a DHCP server and expanding the address pool
The most common technical reason for connection failure is the small range of addresses issued DHCP serverBy default, many routers are configured to issue, for example, 50 or 100 addresses. If the 101st device appears on the network, it simply won't receive an IP address and will be left without internet access. The solution is to expand this range or reduce the address lease time.
To make changes, you need to log into the router's web interface. This is usually done through a browser at 192.168.0.1 or 192.168.1.1After entering your login and password (often admin/admin), you need to find the section responsible for the local network. In the interfaces TP-Link this is usual Network → LAN, V ASUS — Local Network → DHCP Server.
You'll need to find the "Start IP Address" and "End IP Address" or "Pool Size" fields. Increasing the end address will automatically increase the number of possible connections. It's also a good idea to decrease the lease time. If a device is disconnected, its address will be released more quickly and assigned to a new user.
☑️ DHCP setup
It's important not to make the pool too large unnecessarily, although this is rarely a problem for home networks. The main thing is to ensure that the starting and ending addresses are in the same subnet. After applying the settings, the router will require a reboot, and all devices will reconnect, receiving addresses from the new range.
Working with MAC filtering and whitelists
MAC filtering Whitelisting is a powerful security tool that often becomes an obstacle for legitimate users. If the router's "Allow List" mode is enabled, only devices whose physical addresses are included in the database can connect. All others, even those with the Wi-Fi password, will be denied access.
To check this setting, find the section in the router menu Wireless → MAC Filtering or Wireless Mode → MAC FilterThere you'll see a list of rules. If the filtering status is set to "Enable" and the "Allow" rule is selected, you'll need to add the MAC address of the new device to this list.
You can find your MAC address in your phone or laptop settings. On Android, this is usually Settings → About phone → General information, on Windows - command ipconfig /all in the command line. Copy the address in the format XX:XX:XX:XX:XX:XX and add it to the table of allowed devices in the router.
| Filtration type | Description of action | Result for a new device |
|---|---|---|
| Disable | The filter is not working | Access is allowed with knowledge of the password |
| Allow | The white list is working | Access denied if not on the list |
| Deny (Prohibit) | The blacklist is working | Access denied if listed |
In some cases, especially in public places, Captive Portal authentication may be used. In this case, the restriction is lifted only after entering a code from an SMS or making a payment. It's difficult to bypass this programmatically, as verification occurs on the provider's server, not the router.
What to do if the MAC address is not added?
Some routers have a limit on the number of entries in the filtering table (for example, 16 or 32 devices). If the limit is reached, remove old, unused devices or temporarily disable filtering to test your hypothesis.
Removing speed and QoS restrictions
Users often complain not about a complete connection failure, but that the speed drops to zero when connecting a second or third device. This is the function responsible for QoS (Quality of Service) or built-in traffic limiters. The router can prioritize one type of traffic (for example, games) over others (downloads), creating the illusion of blocking.
To manage these settings, find the section QoS or Bandwidth Control in the menu. Here you can see lists of devices with set limits. If a device is limited to 1 Mbps, it won't work faster even with a gigabit connection. You should either delete the rule or set the limit to 0 (unlimited).
It's also worth checking the settings WMM (Wi-Fi Multimedia). While this feature is designed to improve multimedia transmission, on older or cheaper routers, its incorrect operation can lead to connection instability under high load. Try temporarily disabling WMM in the wireless settings (Wireless Settings).
If your ISP is throttling the speed of its equipment (OLT for fiber optics or DSLAM for copper), router settings won't help. In this case, the only solution is to change your tariff plan or use specialized software to encrypt your traffic so the ISP can't see your activity.
⚠️ Note: The QoS settings interface may differ depending on the firmware version. Before changing any settings, write down the current values so you can revert to the original settings.
Bypassing ISP restrictions on Wi-Fi sharing
Mobile operators and some home Internet providers are actively fighting against distributing the Internet to other devices (modem mode or tethering). They analyze the parameter TTL (Time To Live) in data packets. A computer's TTL is usually 64 or 128, while a phone's is 64. When the router forwards the packet, it decrements the TTL by 1. The ISP sees that the TTL has become, say, 63, and understands that the connection is being distributed, after which it blocks the connection.
To remove this limitation, you need to change the TTL on the device that distributes the internet, or on the router, if it supports this feature. In routers based on OpenWrt or DD-WRT This is done via a command in the terminal or a corresponding plugin. This feature is rare on standard home routers (TP-Link, D-Link), but you can find it in the WAN or Internet section.
If you can't change the TTL on your router, you can do it on your computer or phone. On Android, this requires root access and an app like TTL MasterOn Windows, the change is made through the registry. You need to create or modify a parameter DefaultTTL in the branch HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters and set the value to 65 (so that after the router decreases it, it becomes 64).
reg add"HKLM\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters" /v DefaultTTL /t REG_DWORD /d 65 /fAfter making changes to the registry, a device reboot is required. This method is effective against basic ISP checks, but it's worth remembering that operators are constantly improving their detection methods.
Resetting the settings and reflashing the hardware
If the software settings are messed up and access to functions is blocked by someone unknown (for example, a previous landlord or a repairman), the most reliable way to remove all restrictions is a full reset (Factory Reset). This will reset the router to its factory defaults, removing all passwords, filters, and limits.
To perform a reset, find a small hole on the device body with the inscription Reset or DefaultWith the power on, press it with a paperclip and hold it for 10-15 seconds until the indicators blink simultaneously. After this, the router will reboot, and you can set it up again from scratch.
In complex cases where the standard router firmware does not allow flexible connection management, it makes sense to consider installing an alternative operating system, such as OpenWrt or PadavanThese systems provide complete control over the network stack, allowing you to configure complex routing rules, VPN clients, and blocking bypasses.
However, flashing the firmware is a risky operation. Choosing the wrong firmware version or interrupting the process can brick the router. Always check the compatibility of the model and hardware revision before uploading the firmware file.
Risks of reflashing
Installing third-party firmware voids the manufacturer's warranty. Furthermore, some providers (especially fiber optic terminals) may require specific VLAN or PPPoE settings that are already pre-programmed in the standard firmware, but must be entered manually in custom firmware.
Frequently Asked Questions (FAQ)
Why does the router say "Limited" when connecting, even though the password is correct?
Most often, this means the device is unable to obtain an IP address from the DHCP server. Check to see if the address pool is full or if MAC address filtering is enabled. Another possible issue is incompatible encryption standards (for example, an older device is attempting to connect to a WPA3 network).
Is it possible to bypass the mobile operator's device limit?
Technically, this is possible by changing the TTL or using a VPN, but this violates the terms of the contract with the operator. The provider may notice traffic anomalies and block the SIM card or require switching to a more expensive unlimited plan.
How do I know who exactly is connected to my Wi-Fi?
Go to the router admin panel and find the section Status, Device List or ClientsAll active connections with MAC addresses are displayed there. Compare them with the addresses of your devices. If you see a stranger, change your Wi-Fi password and enable MAC address filtering.
Does distance affect connection limitation?
Yes, indirectly. When the signal is weak, data packets are lost, and the device constantly reconnects or requests a new address. If the DHCP server is configured rigorously, it may not be able to distribute addresses quickly or consider the device "dead," creating problems for new connections.
Do I need to reboot my router after changing DHCP settings?
On most modern models, changes take effect immediately. However, for older devices or in the event of critical changes (such as subnet changes), a reboot is recommended to ensure all clients receive the new, correct settings.