Rasberry Pi 3 Wifi Access Point

(Configs via USB keyboard, Mouse and HDMI display)

Equipment:
Raspberry Pi 3B
16GB SD
USB Mouse and Keyboard
HDMI cable for display
OS Raspbian via NOOBS v1.9.0
CAT5 connected to the internet

Make sure you change your password, update and upgrade the OS first.

Install packages
1. CMD: sudo apt-get install dnsmasq hostapd
*select y for yes and enter

2. Configure interface wlan0
CMD: sudo nano /etc/dhcpcd.conf

*add lines to the bottom of file:
	interface wlan0
	static ip_address=172.24.1.1/24

*save(should have the basics on the bottom but ctrl+x, Y, enter)

*you can shutdown the wlan0 before the next step via CMD: sudo ifdown wlan0. Was recommended in another walkthrough I found while trying to figure things out.

3. CMD: sudo nano /etc/network/interfaces (add/edit the below after “allow-hotplug wlan0”)
	iface wlan0 inet static
	address 172.24.1.1
	netmask 255.255.255.0

*add “#” to comment out the next line to look like the below:
#	wpa-conf /etc/wpa_supplicant/wpa-supplicant.conf

*restart dhcpcd via CMD: sudo service dhcpcd restart. Your wlan0 should now have a static IP. You can validate via CMD: ifconfig

4. Configure hostapd, create via command below

CMD: sudo nano /etc/hostapd/hostapd.conf
*now enter the following and save

	interface=wlan0
	driver=nl80211
	ssid=”enter what you want SSID to be”
	hw_mode=g
	channel=1
	macaddr_acl=0
	auth_algs=1
	ignore_broadcast_ssid=0
	wpa=2
	wpa_key_mgmt=WPA-PSK
	wpa_passphrase=”what you want password to be”
	wpa_pairwise=CCMP
	rsn_pairwise=CCMP

*you can check how its going via command below, this should let you see your SSID as a hotspot and connect but you wont get any traffic. You will need to hit ctrl+C to stop service.
CMD: sudo /usr/sbin/hostapd /etc/hostapd/hostapd.conf

5. configure hostapd to find config file on boot
CMD: sudo nano /etc/default/hostapd
*Find line #DEAMON_CONF=”” and remove “#” and edit to look as below:
DAEMON_CONF=”/etc/hostapd/hostapd.conf”

Save

6. Configure dnsmasq, but first move original and create new via command below
CMD: sudo mv /etc/dnsmasq.conf /etc/dnsmasq.conf.orig
CMD: sudo nano /etc/dnsmasq.conf

*now enter the below commands and save

	interface=wlan0
	bind-interfaces
	server=8.8.8.8
	domain-needed
	bogus-priv
	dhcp-range=172.24.1.50,172.24.1.150,12h 

7. Setup ipv4 forwarding
CMD: sudo nano /etc/sysctl.conf
*remove “#” from line net.ipv4.ip_forward=1 and save

CMD: sudo sh –c “echo 1 > /proc/sys/net/ipv4/ip_forward”

8. nat between eth0 and wlan0
CMD: sudo iptables –t nat –A POSTROUTING –o eth0 –j MASQUERADE
CMD: sudo iptables –A FORWARD –i eth0 –o wlan0 –m state --state RELATED,ESTABLISHED –j ACCEPT
CMD: sudo iptables –A FORWARD -i wlan0 –o eth0 –j ACCEPT
* to see what the table created check via CMD’s: sudo iptables –t nat –S and sudo iptables –S
CMD: sudo iptables –t nat –S(should show the below)
-P PREROUTING ACCEPT
-P INPUT ACCEPT
-P OUTPUT ACCEPT
-P POSTROUTING ACCEPT
-A POSTROUTING –o eth0 –j MASQUERADE

CMD: sudo iptables –S
-P INPUT ACCEPT
-P FORWARD ACCEPT
-P OUTPUT ACCEPT
-A FORWARD –i eth0 –o wlan0 –m state --state RELATED,ESTABLISHED –j ACCEPT
-A FORWARD –i wlan0 –o eth0 –j ACCEPT

*now to have them applied every reboot
CMD: sudo sh –c “iptables-save > /etc/iptables.ipv4.nat”

*create file to get dhcpcd to run what we just created
CMD: sudo nano /lib/dhcpcd/dhcpcd-hooks/70-ipv4-nat
*type the below and save
iptables-restore < /etc/iptables.ipv4.nat

Done!

You can check without rebooting via below commands:
CMD: sudo service hostapd start
CMD: sudo service dnsmasq start
*you should now be able to see your SSID, connect and get traffic. Will admit I always had to reboot to get it to work. I also like to reboot as the boot menu lets you know about obvious errors.

Or reboot and connect to your SSID.