Troubleshooting Wi-Fi Stability With Realtek Usb Adapters On Linux
Identifying the Issue
Symptoms of unstable connectivity
An unstable Wi-Fi connection with a Realtek USB adapter on Linux may exhibit various symptoms including intermittent connectivity losses, drastically reduced speeds, inability to connect to certain networks, or authentication failures when trying to join wireless networks. These symptoms typically manifest as frequent disconnects, high latency and packet loss during active connections, or authorization issues when first connecting to access points.
Using journalctl to inspect network manager logs
The journalctl command can be used to review the logs from NetworkManager to help identify issues related to a Realtek USB Wi-Fi adapter. Relevant log entries may pinpoint problems with detecting the hardware, driver errors, connection drops, authentication failures, or other instabilities.
$ sudo journalctl -u NetworkManager
Checking dmesg for disconnect errors
The Linux kernel logging buffer dmesg can also provide insights into Wi-Fi disconnects and other errors with a Realtek USB adapter. Issues with firmware, TX/RX failures, and channel or signal problems may show up here.
$ dmesg | grep -i realtek $ dmesg | grep -i disconnect
Troubleshooting Potential Causes
Trying alternate USB ports
As a first troubleshooting step, try connecting the Realtek Wi-Fi dongle to different USB ports on the computer. Some ports may provide insufficient power to the adapter which could manifest as connectivity problems. Test all available USB-A 3.0/2.0 ports directly on the machine.
Checking adapter firmware
Outdated or incompatible firmware on the Realtek adapter could also lead to the connectivity issues. Verify the device has the latest driver and firmware from Realtek before further troubleshooting. The Linux kernel may also need updated Realtek rtlxxx firmware files.
$ lsusb -v | grep -e Firmware -e Realtek $ dmesg | grep rtl #check loaded firmware revision
Inspecting signal strength and interference
Weak wireless signals or interference from nearby devices can manifest as connectivity problems. Check the signal strength values in nmcli (or iwconfig) output when connected to identify any marginal signals. Switch channels on the wireless router and use a Wi-Fi analyzer to detect interference or congestion.
$ nmcli device wifi list $ nmcli device wifi rescan $ iwlist wlp3s0 scan | egrep 'Signal|ESSID'
Verifying Wi-Fi power saving settings
Overly aggressive Wi-Fi power saving measures by the Linux kernel can sometimes lead to connectivity issues with Realtek adapters. Inspect the power saving options for the wireless interface using iw to identify enabled powersave policies.
$ iw wlp3s0 get power_save
Testing hardware defects
Faulty hardware like a poor antenna or USB connector problems in the Realtek adapter could manifest as connectivity instability in some cases. Try flexing the USB cable and antenna joint while connected to see if connects drop. Also attempt using a USB extension cable to isolate USB port issues.
Configuration Changes for Stability
Adjusting channel bandwidth
The default 20/40MHz channel width used by most wireless routers can sometimes cause issues for Realtek devices. Switch the router to use a 20MHz only mode and channel bandwidth setting to see if it stabilizes the connection.
$ nmcli c modify MyWiFi802.11-a.bg.mode 20MHz
Setting a static IP address
By default NetworkManager assigns dynamic IP addresses to Wi-Fi adapters which can trigger connectivity loss in some scenarios. Configure a static IP instead of DHCP by specifying a fixed IP and DNS servers in NetworkManager.
$ nmcli con modify MyWiFi802.11-a ipv4.method manual ipv4.addresses "10.10.0.23/24"
Disabling Wi-Fi power management
Power saving mechanisms in the Wi-Fi stack can sometimes disrupt connectivity for Realtek devices. Try disabling any enabled power saving options.
$ iw wlp3s0 set power_save off
Increasing transmit power if supported
Some Realtek Wi-Fi adapters allow increasing the TX power which can improve signal stability in some environments. Use iw to check if txpower settings are available and increase within legal limits if necessary.
$ iw list | grep txpower $ iw dev wlp3s0 set txpower fixed 3000
Trying an alternate Linux kernel
Incompatibility issues between the Realtek adapter drivers and the Linux kernel version can trigger connectivity problems in some cases. Attempt booting an older or newer kernel like a mainline build to test if it stabilizes the wireless connection.
$ uname -r $ dmesg | grep --color -e rtl
Additional Troubleshooting Steps
Testing the adapter on another OS
To rule out hardware defects in the Realtek adapter, try booting into a Windows or Linux live USB and testing Wi-Fi connectivity. Persistent issues across different OSes would indicate a potential hardware fault.
Contacting Realtek support
If all typical troubleshooting steps have been exhausted, contact Realtek support with debug logs and describe the connectivity instability in detail. Realtek may suggest targeted firmware updates, driver patches or other reconfiguration to stabilize problematic adapters in some cases.
