Establishing a wireless connection between two remote locations often becomes a critical task for owners of private homes, summer cottages, or small offices. Technology Wi-Fi bridge allows internet traffic to be transmitted over distances of several kilometers without the need for expensive fiber optic or copper cable. The company's devices are at the center of this area. MikroTik, which are renowned for their flexibility and stability of operation even in complex radio channels.
Many users mistakenly believe that creating a channel is as simple as enabling client mode on the router, but the actual connection architecture is much more complex. Understanding how data packets travel through the air and are transformed within the local network is essential for troubleshooting speed issues and connection interruptions. In this article, we'll explore the fundamental principles of bridging, the differences between modes, and the intricacies of hardware configuration.
The basic idea is that one device acts as an access point, while another connects to it as a client. Traffic is then forwarded to the second router, creating a unified local network. This creates the illusion that the computers on the remote end are directly connected to the main router via a cable. However, implementing this setup requires proper configuration of interfaces and security protocols.
How a wireless bridge works
The basis of the work Wi-Fi bridge There's a wireless interface operating mode called Station Bridge. Unlike the standard Station mode, which is used in phones and laptops for internet access, Bridge mode requires all devices behind the client router to be visible to the main router's network. This is achieved by forwarding MAC addresses over the radio channel.
When a data packet from a computer connected to the second router is transmitted, it is not disguised as the router's own address. Instead, the MikroTik device is in wireless mode. Station Bridge Broadcasts the original MAC addresses of end devices over a wireless connection. The main router (Access Point) sees these addresses as if they were directly connected to its LAN port.
β οΈ Attention: For the bridge to work correctly in Station Bridge mode, it is critical that the option is enabled on the access point (main router) side.
WDS ModeorDynamic WDSWithout this, MAC address forwarding will not work, and the connection will not occur.
There is also a mode Bridge on the receiving device side, which is a more modern analogue of Station Bridge and often works more reliably with proprietary protocol extensions NV2The choice of a specific mode depends on the version of RouterOS and the type of hardware used, whether it is popular hAP or street SXT.
Mode Differences: Station vs. Station Bridge
Understanding the difference between standard client mode and bridge mode is key to successful setup. In standard mode Station The router receives a single IP address from the remote network and distributes it to its clients via NAT (Network Address Translation). In this case, all devices behind the client router are hidden from the main network.
Mode Station Bridge It works differently: it disables NAT for the wireless interface and allows device MAC addresses to "pass through" the radio channel. This is necessary if you want devices in different buildings to be on the same subnet and see each other's network printers, NAS storage, or security cameras.
The technical limitations of Station Bridge mode should also be considered when designing a network. For example, WPA2-Personal with certain encryption settings is often unavailable in this mode, and WDS or open networks with MAC address authentication are preferable. Furthermore, Bridge mode requires that the SSID and frequency channels match perfectly.
Why might Station Bridge not work?
Station Bridge mode requires WDS support on the access point. If the main router is a provider device with proprietary firmware, it may block multiple MAC addresses or not support WDS. In such cases, you must use Station mode with VLAN forwarding or tunnel configuration (L2TP/GRE), which is more complex but more versatile.
When choosing equipment of the series MikroTik It's important to note that some older models may have limitations on the number of MAC addresses that can be forwarded in bridge mode. For larger office networks, it's better to use models with more powerful processors, such as NetMetal or Wireless Wire.
Necessary equipment and requirements
To build a high-quality communication channel, simply purchasing two identical routers isn't enough. It's also important to consider the frequency range, channel width, and receiver sensitivity. MikroTik devices operate in the 2.4 GHz and 5 GHz bands, with 5 GHz being preferred for bridging due to its lower noise level and greater available channel width.
The most important parameter is a clear line of sight between the antennas. Any obstacle, be it a tree, the wall of a neighboring house, or even dense foliage, can critically reduce speed or completely disrupt the connection. For outdoor links, devices with built-in antennas are used, such as SXT or LHG, which provide high signal directivity.
Below is a comparison table of popular MikroTik bridging device series:
| Series of devices | Frequency range | Antenna type | Recommended use |
|---|---|---|---|
| MikroTik SXT | 2.4 / 5 GHz | Built-in panel | Short and medium links (up to 2 km) |
| MikroTik LHG | 5 GHz / 60 GHz | Built-in parabolic | Long links with high (up to 5+ km) |
| MikroTik mANT | 2.4 / 5 GHz | Sector / Omni | Connecting multiple clients (Point-to-Multipoint) |
| MikroTik wAP | 2.4 / 5 GHz | Internal omnidirectional | Internal bridges within a single building |
When choosing a model, also pay attention to the standard support 802.11ac (Wave 2) or new Wi-Fi 6If your client network devices require high speeds, older 802.11n standards can become a bottleneck, limiting actual data transfer rates to 20-30 Mbps.
Step-by-step access point setup (Master)
Setup begins with configuring the main device that will distribute the internet. First, you need to create a security profile, as data transfer over an open channel is not allowed. In the menu Wireless go to the tab Security Profiles and create a new profile with a name, for example, bridge-profile.
In the profile settings, select the mode dynamic keys and enter the password in the field WPA2 Pre-Shared KeyIt is important to use encryption. AES-CCM, as it provides the best performance and security. After saving the profile, we move on to configuring the wireless interface itself.
βοΈ Setting up a Master device
In the wireless interface properties (double click on the wlan1 interface) set the operating mode ap-bridgeIn the field SSID Enter the name of your network that the client will see. In the section WDS Mode select a value dynamic or static (for a static one, you will need to enter the client's MAC address manually, which is more reliable, but less flexible).
Don't forget to manually assign the channel frequency to prevent the router from "jumping" between frequencies during a reboot. For the 5 GHz band in Russia, channels 36, 40, 44, 48, and so on are available. Channel width (channel-width) must be set to the value 20/40/80mhz Ce for maximum speed, if the airwaves are not too noisy.
Client device configuration (Slave)
On the receiving device, the procedure is mirror-opposite, but has its own nuances. Go to the wireless interface settings and change the operating mode (Mode) on station-bridgeThis parameter turns the router into a transparent bridge that forwards MAC addresses.
In the field SSID Enter the network name of the main router. If you are using the mode station-bridge, field WDS Mode should also be activated here (usually dynamic). After applying the settings, the device will begin searching for the network and attempting to associate.
β οΈ Attention: When switching the wireless interface mode on a client device, you may lose connection to it if you're connected via Wi-Fi. It's best to make all changes on the client using an Ethernet cable.
To automate the connection process, you can use the function Scan in the wireless interface window. Select the desired network from the list and click the button ConnectIf all security settings match, the connection status will change to running, and a record of successful association will appear in the logs.
After establishing the link, you need to check the IP settings. If the master router distributes IP addresses (DHCP Server), then the DHCP Server on the client device's LAN port must be disabled to avoid address conflicts. In this setup, the client router acts as a switch with routing functionality, but the master router handles the primary address distribution logic.
Signal diagnostics and optimization
After physically installing the antennas, the fine-tuning stage begins. Even ideal theoretical tuning can be disrupted by interference. Use the built-in tool Sniffer or Torch on the menu Toolsto analyze the traffic passing through and ensure that packets are not lost.
The key parameter of communication quality is CCQ (Client Connection Quality). This is the percentage of connection efficiency. If CCQ drops below 60-70%, speed will drop sharply, even if the signal strength (signal strength) high. A low CCQ often indicates interference or signal reflections.
To improve channel stability, it is recommended:
- π‘ Use a narrow channel width (20 MHz) over long distances to improve interference immunity.
- π Disable unused standards (for example, leave only 802.11ac, if old devices are not needed).
- π Update RouterOS to the latest stable version to get wireless driver improvements.
It's also worth paying attention to antenna polarization. If one antenna is installed vertically and the other horizontally, you'll lose up to 20 dB of signal, which is equivalent to a broken connection. When installing outdoor links, strictly ensure that the polarization matches (usually vertical for point-to-point links).
What is AirMax or Ubiquiti in the context of MikroTik?
MikroTik devices use proprietary protocols (NV2, TDMA), which are incompatible with Ubiquiti AirMax equipment. Building a bridge between these vendors using standard tools is impossible; universal operating modes are required, which significantly reduce speed.
Common mistakes and their solutions
One of the most common problems is a network loop or IP address conflict, when two DHCP servers begin handing out addresses on the same network. This results in internet connection intermittently coming on and off. There's only one solution: disable the DHCP server completely on the client router in bridged mode.
Another mistake is incorrect firewall configuration. Sometimes users forget that in bridged mode, firewall rules can also be applied to forwarded traffic. If you can't ping devices behind the bridge, check the firewall chain. forward on the menu IP -> Firewall.
If the link is up but the speed is low, check the settings Distance in the wireless interface. For long links (more than 1 km), you must manually set the distance in kilometers or enable auto-install, so that the protocol correctly calculates timeouts for waiting for packet acknowledgement (ACK).
Why is the bridge working slowly even though the signal is full?
The problem is often caused by Wi-Fi's half-duplex mode. The speed is split in half for receiving and transmitting. Interference from neighboring networks on the same frequency can also reduce speed. Try changing the channel or channel width.
Is it possible to connect three routers in a chain using a bridge?
Theoretically, it's possible (using WDS or Station Bridge mode with pass-through), but this will dramatically reduce speed, as each hop cuts the airtime bandwidth in half. For three points, it's better to use a "star" configuration from a single, powerful base station or a (wired) connection between the intermediate points.
Do I need a static IP to set up a bridge?
The bridge itself (L2) doesn't require IP addresses; it operates at the MAC address level. However, for ease of management and access to the router interface behind the bridge, it's best to assign a static IP address or reserve a MAC address in the main router's DHCP server.
Does weather affect the operation of the Wi-Fi bridge?
Yes, heavy rain, snow, or fog can weaken the signal, especially at frequencies of 5 GHz and above (60 GHz). When designing a link, always include a fade margin of at least 15-20 dB to prevent connection loss during heavy rain.