AP mode for Wifi on Ubuntu

iw list to check if it support AP mode.

$ iw list
...
...
Supported interface modes:
               * IBSS
               * managed
               * AP
               * P2P-client
               * P2P-GO
...
...

//It supports the Frequencies
iw list | grep -A20 Frequencies
$ iw list | grep -A20 Frequencies
                Frequencies:
                        * 2412 MHz [1] (20.0 dBm)
                        * 2417 MHz [2] (20.0 dBm)
                        * 2422 MHz [3] (20.0 dBm)
                        * 2427 MHz [4] (20.0 dBm)
                        * 2432 MHz [5] (20.0 dBm)
                        * 2437 MHz [6] (20.0 dBm)
                        * 2442 MHz [7] (20.0 dBm)
                        * 2447 MHz [8] (20.0 dBm)
                        * 2452 MHz [9] (20.0 dBm)
                        * 2457 MHz [10] (20.0 dBm)
                        * 2462 MHz [11] (20.0 dBm)
                        * 2467 MHz [12] (20.0 dBm) (no IR)
                        * 2472 MHz [13] (20.0 dBm) (no IR)
                        * 2484 MHz [14] (disabled)
        Band 2:
                Capabilities: 0x863
                        RX LDPC
                        HT20/HT40
                        Static SM Power Save
                        RX HT20 SGI
--
                Frequencies:
                        * 5180 MHz [36] (20.0 dBm)
                        * 5200 MHz [40] (20.0 dBm)
                        * 5220 MHz [44] (20.0 dBm)
                        * 5240 MHz [48] (20.0 dBm)
                        * 5260 MHz [52] (20.0 dBm) (no IR)
                        * 5280 MHz [56] (20.0 dBm) (no IR)
                        * 5300 MHz [60] (20.0 dBm) (no IR)
                        * 5320 MHz [64] (20.0 dBm) (no IR)
                        * 5500 MHz [100] (20.0 dBm) (no IR)
                        * 5520 MHz [104] (20.0 dBm) (no IR)
                        * 5540 MHz [108] (20.0 dBm) (no IR)
                        * 5560 MHz [112] (20.0 dBm) (no IR)
                        * 5580 MHz [116] (20.0 dBm) (no IR)
                        * 5600 MHz [120] (20.0 dBm) (no IR)
                        * 5620 MHz [124] (20.0 dBm) (no IR)
                        * 5640 MHz [128] (20.0 dBm) (no IR)
                        * 5660 MHz [132] (20.0 dBm) (no IR)
                        * 5680 MHz [136] (20.0 dBm) (no IR)
                        * 5700 MHz [140] (20.0 dBm) (no IR)
                        * 5720 MHz [144] (disabled)

use nmcli to enable, nmcli version: 1.36.6

$ sudo nmcli d wifi hotspot ifname "wifi-if-name" ssid "ssid-name" password "ssid-passwd"

ex:
$ sudo nmcli d wifi hotspot ifname wlan0 ssid TestHop password 12345678
[sudo] password for nvidia:

Device 'wlan0' successfully activated with '....................'.
Hint: "nmcli dev wifi show-password" shows the Wi-Fi name and password.
nvidia@tegra-ubuntu:~
$ nmcli connection show
NAME                UUID                                  TYPE      DEVICE
Hotspot             ....................................  wifi      wlan0
l4tbr0              ....................................  bridge    l4tbr0
Wired connection 1  ....................................  ethernet  --

It can set more parameters.

$ sudo nmcli connection add type wifi ifname wlP1p1s0 con-name MyAP autoconnect no ssid TestHop
Connection 'MyAP' (f57dec29-c426-4942-ad02-0931587e72dc) successfully added.

$ sudo nmcli connection modify MyAP 802-11-wireless.mode ap

$ sudo nmcli connection modify MyAP 802-11-wireless.band a   //a: 5G, bg: 2.4

$ sudo nmcli connection modify MyAP 802-11-wireless.channel 36  //5G channel

$ sudo nmcli connection modify MyAP 802-11-wireless-security.key-mgmt wpa-psk

$ sudo nmcli connection modify MyAP 802-11-wireless-security.psk "12345678"

$ sudo nmcli connection up MyAP
Error: Connection activation failed: IP configuration could not be reserved (no available address, timeout, etc.)
Hint: use 'journalctl -xe NM_CONNECTION=f57dec29-c426-4942-ad02-0931587e72dc + NM_DEVICE=wlP1p1s0' to get more details.


$ sudo nmcli connection modify MyAP ipv4.method shared

$ sudo nmcli connection modify MyAP ipv6.method ignore

$ sudo nmcli connection up MyAP
Connection successfully activated (D-Bus active path: /org/freedesktop/NetworkManager/ActiveConnection/4)

Deleting APN in Network Manager GUI

$ sudo ls /etc/NetworkManager/system-connections/xxx.nmconnection
$ sudo nmcli connection delete xxx_name
$ sudo systemctl restart NetworkManager