Setup Wi-Fi Access Point

This article will show how to setup the Jetson Orin Nano with a Wi-Fi Access Point such that other wireless devices (such as your mobile phone) can connect to the device’s wired network.

Info

Each command is specific to your setup - pay attention to the key words from the commands

"wlP1p1s0" (Wi-Fi interface which could change depending on your system)
"enP8p1s0" (Ethernet interface which could change depending on your system)
"192.168.1.204" (static IP address you can set)

Find your device’s Wi-Fi interface (wlP1p1s0 in this case)

$ iw dev
phy#0
Interface wlP1p1s0
        ifindex 2
        wdev 0x1
        addr 9c:c7:d3:97:62:ad
        type managed
        txpower -100.00 dBm

Verify Wi-Fi AP support - you must see AP in supported modes

$ sudo iw list | sed -n '/Supported interface modes:/,/Band/p'
        Supported interface modes:
                * IBSS
                * managed
                * AP
                * P2P-client
                * P2P-GO
        Band 1:

Install required packages

sudo apt update
sudo apt install -y hostapd dnsmasq iptables-persistent

Prevent NetworkManager from controlling Wi-Fi AP interface. Create a NetworkManager override so wlP1p1s0 (specific to your system) is unmanaged
```
sudo tee /etc/NetworkManager/conf.d/99-unmanaged-wifi.conf >/dev/null <<'EOF'
[keyfile]
unmanaged-devices=interface-name:wlP1p1s0
EOF
```
Restart NetworkManager
```
sudo systemctl restart NetworkManager
```

Assign static IP to Wi-Fi interface at boot. Create a small systemd unit

sudo tee /etc/systemd/system/ap-interface.service >/dev/null <<'EOF'
[Unit]
Description=Configure AP interface wlP1p1s0
After=network.target
Before=hostapd.service dnsmasq.service
[Service]
Type=oneshot
ExecStart=/sbin/ip link set wlP1p1s0 up
ExecStart=/sbin/ip addr flush dev wlP1p1s0
ExecStart=/sbin/ip addr add 192.168.1.204/24 dev wlP1p1s0
RemainAfterExit=yes
[Install]
WantedBy=multi-user.target
EOF

Configure hostapd by creating hostapd config. Note you can set the access point ssid and wpa_passphrase. The wpa_passphrase must be at least 8 characters

sudo tee /etc/hostapd/hostapd.conf >/dev/null <<'EOF'
interface=wlP1p1s0
driver=nl80211
ssid=my_ssid
hw_mode=g
channel=6
wmm_enabled=1
country_code=CA
ieee80211n=1
ieee80211d=1
auth_algs=1
wpa=2
wpa_key_mgmt=WPA-PSK
rsn_pairwise=CCMP
wpa_passphrase=mypassphrase
EOF

Point hostapd service to this config

sudo sed -i 's|^#\?DAEMON_CONF=.*|DAEMON_CONF="/etc/hostapd/hostapd.conf"|' /etc/default/hostapd

Configure dnsmasq for DHCP by creating AP DHCP config

sudo tee /etc/dnsmasq.d/jetson-ap.conf >/dev/null <<'EOF'
interface=wlP1p1s0
bind-interfaces
dhcp-range=192.168.1.50,192.168.1.150,255.255.255.0,24h
dhcp-option=3,192.168.1.204
dhcp-option=6,1.1.1.1,8.8.8.8
EOF

Enable IPv4 forwarding

sudo tee /etc/sysctl.d/99-jetson-ap.conf >/dev/null <<'EOF'
net.ipv4.ip_forward=1
EOF
sudo sysctl --system

Add NAT and forwarding rules (Wi-Fi → Ethernet); your ethernet can be found via ip addr → enP8p1s0 in this case

sudo iptables -t nat -A POSTROUTING -o enP8p1s0 -j MASQUERADE
sudo iptables -A FORWARD -i enP8p1s0 -o wlP1p1s0 -m state --state RELATED,ESTABLISHED -j ACCEPT
sudo iptables -A FORWARD -i wlP1p1s0 -o enP8p1s0 -j ACCEPT
sudo netfilter-persistent save

Unmask hostapd

sudo systemctl unmask hostapd
sudo systemctl enable hostapd

Enable and start services

sudo systemctl daemon-reload
sudo systemctl enable ap-interface hostapd dnsmasq
sudo systemctl restart ap-interface
sudo systemctl restart hostapd
sudo systemctl restart dnsmasq

Verify the static IP address

$ ip addr show wlP1p1s0
2: wlP1p1s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
    link/ether f8:3d:c6:56:fe:93 brd ff:ff:ff:ff:ff:ff
    inet 192.168.1.204/24 scope global wlP1p1s0
    valid_lft forever preferred_lft forever

Test on your mobile
- Connect to SSID my_ssid
- Enter WPA password mypassphrase

Check System Status

systemctl status hostapd --no-pager
systemctl status dnsmasq --no-pager
ip -4 addr show wlP1p1s0
sudo journalctl -u hostapd -n 50 --no-pager

System Debugging

If you get the error trying to restart hostapd

$ sudo systemctl restart hostapd
Job for hostapd.service failed because the control process exited with error code.
See "systemctl status hostapd.service" and "journalctl -xeu hostapd.service" for details.

Check the service status

$ sudo journalctl -u hostapd -n 80 --no-pager
Apr 30 12:48:00 systemd[1]: Stopped Access point and authentication server for Wi-Fi and Ethernet.
Apr 30 12:48:00 systemd[1]: Starting Access point and authentication server for Wi-Fi and Ethernet...
Apr 30 12:48:00 hostapd[9829]: Line 14: invalid WPA passphrase length 5 (expected 8..63)
Apr 30 12:48:00 hostapd[9829]: WPA-PSK enabled, but PSK or passphrase is not configured.
Apr 30 12:48:00 hostapd[9829]: 2 errors found in configuration file '/etc/hostapd/hostapd.conf'
Apr 30 12:48:00 hostapd[9829]: Failed to set up interface with /etc/hostapd/hostapd.conf
Apr 30 12:48:00 hostapd[9829]: Failed to initialize interface
Apr 30 12:48:00 systemd[1]: hostapd.service: Control process exited, code=exited, status=1/FAILURE
Apr 30 12:48:00 systemd[1]: hostapd.service: Failed with result 'exit-code'.
Apr 30 12:48:00 systemd[1]: Failed to start Access point and authentication server for Wi-Fi and Ethernet.

Check the wpa_passphrase and this must be at least 8 characters, up to 63.

If the AP does not start, run these commands

rfkill list
sudo rfkill unblock all
sudo ip link set wlP1p1s0 up
sudo iw reg set US
sudo systemctl restart hostapd
sudo journalctl -u hostapd -n 80 --no-pager