Changing which WiFi Adapter is in Use

This guide shows how to change which WiFi adapter (network card) is used for a specific network connection across different Linux network management systems.

Why Change WiFi Adapters?

• Multiple WiFi cards: When you have multiple WiFi adapters (built-in + USB)
• Performance optimization: Using a faster or better-positioned adapter
• Troubleshooting: Testing different adapters when experiencing connectivity issues
• Hardware-specific features: Some adapters support different standards (802.11ac, ax, etc.)

Method 1: NetworkManager (Most Common)

Graphical Interface

On systems using NetworkManager (most desktop distributions), press ALT+F2 to open the run dialog, then paste the following and press Enter:

nm-connection-editor

1. In the Network Connections window, highlight the WiFi network you want to modify
2. Click on the Gear Icon (edit button) at the bottom left
3. In the connection editor that opens, navigate to the WiFi tab
4. Choose which WiFi adapter you wish to use by changing the Device dropdown
5. Click Save to apply the changes

Command Line Interface

# List all network devices (shows device names and types)
nmcli device status

# Show only WiFi devices
nmcli device status | grep wifi

# List existing WiFi connections
nmcli connection show | grep wifi

# Modify a connection to use a specific device
nmcli connection modify "Your-WiFi-Name" 802-11-wireless.device wlan1

# Alternative: Delete and recreate connection with specific device
nmcli connection delete "Your-WiFi-Name"
nmcli device wifi connect "SSID-Name" password "your-password" ifname wlan1

Method 2: systemd-networkd

For systems using systemd-networkd:

# List available network devices
networkctl list

# Check device status
networkctl status wlan0
networkctl status wlan1

# Create/edit network configuration file
sudo nano /etc/systemd/network/25-wireless.network

Example configuration file (/etc/systemd/network/25-wireless.network):

[Match]
Name=wlan1
Type=wlan

[Network]
DHCP=yes

[DHCP]
UseDNS=yes

Apply changes:

sudo systemctl restart systemd-networkd

Method 3: wpa_supplicant + dhcpcd

For manual WiFi management:

# List WiFi interfaces
sudo iw dev

# Scan for networks on specific interface
sudo iw dev wlan1 scan | grep SSID

# Create wpa_supplicant configuration
sudo wpa_passphrase "SSID-Name" "password" | sudo tee /etc/wpa_supplicant/wpa_supplicant-wlan1.conf

# Connect using wpa_supplicant
sudo wpa_supplicant -B -i wlan1 -c /etc/wpa_supplicant/wpa_supplicant-wlan1.conf

# Get IP address via DHCP
sudo dhcpcd wlan1

Method 4: netplan (Ubuntu/Debian)

For systems using netplan:

# Edit netplan configuration
sudo nano /etc/netplan/01-network-manager-all.yaml

Example configuration:

network:
  version: 2
  wifis:
    wlan1:
      dhcp4: true
      access-points:
        "Your-SSID":
          password: "your-password"

Apply configuration:

sudo netplan apply

Method 5: ifupdown (Legacy)

For older systems using ifupdown:

# Edit interfaces file
sudo nano /etc/network/interfaces

Add configuration:

auto wlan1
iface wlan1 inet dhcp
    wpa-ssid "Your-SSID"
    wpa-psk "your-password"

Apply changes:

sudo ifdown wlan0  # Disable current adapter
sudo ifup wlan1    # Enable new adapter

Useful Commands for All Methods

Identify WiFi Adapters

# List all network interfaces
ip link show

# Show only wireless interfaces
iwconfig

# Modern alternative to iwconfig
iw dev

# Check USB WiFi adapters
lsusb | grep -i wireless

# Check PCI WiFi adapters
lspci | grep -i wireless

Check Adapter Capabilities

# Check supported standards and frequencies
iw list

# Check specific adapter info
iw dev wlan0 info
iw dev wlan1 info

# Check link quality and signal strength
iwconfig wlan0
iwconfig wlan1

Monitor Connection Status

# Watch connection status (NetworkManager)
watch nmcli device status

# Monitor systemd-networkd
watch networkctl status

# Check active connections
ss -tuln | grep :22  # SSH connections
ss -tuln | grep :80  # HTTP connections

Troubleshooting Tips

1. Verify adapter is recognized: lsusb or lspci | grep -i wireless
2. Check for driver issues: dmesg | grep -i wireless
3. Ensure adapter is not blocked: rfkill list
4. Test adapter functionality: iw dev wlan1 scan
5. Check signal strength: iwconfig or nmcli device wifi list

Remember to replace adapter names (wlan0, wlan1) and network names with your actual device names and SSID.