Bring up wireless interfaces

Topics in this section,

• Learnings in this section

• Version Info

• Bring up wireless interfaces

  • STEP 1: Remove old packages

  • STEP 2: Install required libraries

  • STEP 3: Stop ongoing wireless activities

  • STEP 4: Check wireless interface status before connection

  • STEP 5: Check ifconfig interface status before connection

Learnings in this section

• In this section, you are going to learn

• How to bring up wireless interfaces

Version Info

#	Version
Ubuntu	Ubuntu 22.04 64 bit
Linux Kernel	6.5.0
Supplicant	wpa_supplicant 2.10
Hostapd	hostapd 2.10

Bring up wireless interfaces

STEP 1: Remove old packages

test:~$ cd $HOME

test:~$ rm -rf hostap* wpa_supp*

STEP 2: Install required libraries

• Make sure internet is available in laptop to download libraries

test:~$ sudo apt install libnl-genl-3-dev libnl-3-dev libdbus-glib-1-dev

STEP 3: Stop ongoing wireless activities

• Internet is cut-off after this !

• Stop any active wifi services

test:~$ sudo killall wpa_supplicant

test:~$ sudo killall wpa_cli

test:~$ sudo killall hostapd

test:~$ sudo killall hostapd_cli

• Stop any active networking services

test:~$ sudo killall dhclient

test:~$ sudo systemctl stop NetworkManager.service

• Make sure Radio chips are in active state

test:~$ sudo rfkill unblock all

test:~$ sudo rfkill list all
9: phy0: Wireless LAN
        Soft blocked: no
        Hard blocked: no
10: phy1: Wireless LAN
        Soft blocked: no
        Hard blocked: no
11: phy2: Wireless LAN
        Soft blocked: no
        Hard blocked: no

• Make sure the Wi-Fi network interfaces are UP !

• Bring up wlan1 interface for station

test:~$ sudo ifconfig wlan1 up

• Bring up wlan0 interface for ap

test:~$ sudo ifconfig wlan0 up

STEP 4: Check wireless interface status before connection

• Make sure mode is set to managed in wlan1 interface

test:~$ sudo iwconfig wlan1
wlan1     IEEE 802.11  ESSID:off/any
          Mode:Managed  Access Point: Not-Associated   Tx-Power=20 dBm
          Retry short limit:7   RTS thr:off   Fragment thr:off
          Encryption key:off
          Power Management:off

• Make sure mode is set to managed in wlan0 interface

test:~$ sudo iwconfig wlan0
wlan0     IEEE 802.11  ESSID:off/any
          Mode:Managed  Access Point: Not-Associated   Tx-Power=20 dBm
          Retry short limit:7   RTS thr:off   Fragment thr:off
          Encryption key:off
          Power Management:off

STEP 5: Check ifconfig interface status before connection

test:~$ sudo ifconfig wlan1
wlan1: flags=4099<UP,BROADCAST,MULTICAST>  mtu 1500
        ether 02:00:00:00:01:00  txqueuelen 1000  (Ethernet)
        RX packets 0  bytes 0 (0.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 0  bytes 0 (0.0 B)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

test:~$ sudo ifconfig wlan0
wlan0: flags=4099<UP,BROADCAST,MULTICAST>  mtu 1500
        ether 02:00:00:00:00:00  txqueuelen 1000  (Ethernet)
        RX packets 0  bytes 0 (0.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 0  bytes 0 (0.0 B)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0