# Raspberry Pi Access Point

for the Raspberry Pi 3, I used [this page](https://frillip.com/using-your-raspberry-pi-3-as-a-wifi-access-point-with-hostapd/) except for the /etc/network/interface which I did as below.

Of course, first I had to do [Basic Raspberry Pi Set-up](https://wiki.rg.net/wiki/RaspberryPi).

So I wanted to see the state of the USB card and driver

```
dmesg | grep rtl
[    6.875478] usbcore: registered new interface driver rtl8192cu
lsusb
Bus 001 Device 002: ID 0424:9512 Standard Microsystems Corp. 
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 001 Device 003: ID 0424:ec00 Standard Microsystems Corp. 
Bus 001 Device 004: ID 0bda:8176 Realtek Semiconductor Corp. RTL8188CUS 802.11n WLAN Adapter
```

Next was installing hostapd and some utilities

```
apt-get install hostapd bridge-utils iw iptables-persistent
```

I wanted to run a wireless router, so followed, well adapted, the instructions at [http://qcktech.blogspot.com/2012/08/raspberry-pi-as-router.html](http://qcktech.blogspot.com/2012/08/raspberry-pi-as-router.html) and [http://learn.adafruit.com/setting-up-a-raspberry-pi-as-a-wifi-access-point/overview](http://learn.adafruit.com/setting-up-a-raspberry-pi-as-a-wifi-access-point/overview) and [http://secsup.net/index.php/shaded_grey/comments/comcast_consumer_ipv6_configuration_raspberry_pi_as_bridge_base_station/](http://secsup.net/index.php/shaded_grey/comments/comcast_consumer_ipv6_configuration_raspberry_pi_as_bridge_base_station/)

Edit/create /etc/hostapd/hostapd.conf as follows:

```
interface=wlan0
driver=nl80211
ssid=rgnet-pi3
hw_mode=g
channel=6
macaddr_acl=0
auth_algs=1
ignore_broadcast_ssid=0
wpa=2
wpa_passphrase=arbitrarykeys
wpa_key_mgmt=WPA-PSK
wpa_pairwise=TKIP
rsn_pairwise=CCMP
```

And hack /etc/default/hostapd to the following (and be sure to remove the #ash)

```
DAEMON_CONF="/etc/hostapd/hostapd.conf"
```

Then configure /etc/network/interfaces 

```
auto lo
 iface lo inet loopback

auto eth0
  iface eth0 inet dhcp

auto wlan0
  iface wlan0 inet static
  address 100.64.64.1/24
```

Running an access point requires a dhcp server

```
apt-get install isc-dhcp-server
```

In /etc/dhcp/dhcpd.conf, make it authoritative by uncommenting

```
#authoritative;
```

and then hack

```
default-lease-time 3600;
max-lease-time 7200;
option domain-name "psg.com rg.net rpki.net";
option domain-name-servers 8.8.8.8, 8.8.4.4;
option ntp-servers 50.135.235.34;

# No service will be given on this subnet, but declaring it helps the
# DHCP server to understand the network topology.

subnet 192.168.2.0 netmask 255.255.255.0 {
  }

subnet 100.64.64.0 netmask 255.255.255.0 {
  range 100.64.64.10 100.64.64.100;
  option broadcast-address 100.64.64.255;
  option routers 100.64.64.1;
  }
```

Network 192.168.2.0 is the ether over which I am working doing the install. 

And then start the dhcpd to test it

```
service isc-dhcp-server start
```

Get autostart scripts

```
ln -s /etc/init.d/networking /etc/rc2.d/S00networking
ln -s /etc/init.d/hostapd /etc/rc2.d/S02hostapd
ln -s /etc/init.d/isc-dhcp-server /etc/rc2.d/S02isc-dhcp-server 
```

That last may already exist from the apt-get install.

To allow forwarding, in /etc/sysctl.conf, uncomment

```
net.ipv4.ip_forward=1
```

Set up the NAT in iptables

```
iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE
iptables -A FORWARD -i eth0 -o wlan0 -m state --state RELATED,ESTABLISHED -j ACCEPT
iptables -A FORWARD -i wlan0 -o eth0 -j ACCEPT
```

And the IPTABLE entry for the NAT

```
iptables-save | tee /etc/iptables/rules.v4
```

The `iptables-persistent` will see this id loaded on boot.

It would be wise to test with

```
# iptables -t nat -S
-P PREROUTING ACCEPT
-P INPUT ACCEPT
-P OUTPUT ACCEPT
-P POSTROUTING ACCEPT
-A POSTROUTING -o eth0 -j MASQUERADE
# 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
```

Sad news

```
# /usr/sbin/hostapd -B -P /var/run/hostapd.pid /etc/hostapd/hostapd.conf 
-bash: /usr/sbin/hostapd: No such file or directory
```

strangely enough, this worked

```
apt remove hostapd
apt install hostapd
[    3.189542] usb 1-1.2: new high-speed USB device number 4 using dwc_otg
[    3.321819] usb 1-1.2: New USB device found, idVendor=0bda, idProduct=8176
[    3.330893] usb 1-1.2: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[    3.339977] usb 1-1.2: Product: 802.11n WLAN Adapter
[    3.346536] usb 1-1.2: Manufacturer: Realtek
[    3.352383] usb 1-1.2: SerialNumber: 00e04c000001
[    4.800101] udevd[157]: starting version 175
[    7.230707] bcm2708-i2s bcm2708-i2s.0: Failed to create debugfs directory
[    7.499568] usbcore: registered new interface driver rtl8192cu
pi-3:/root# /usr/sbin/hostapd -B -P /var/run/hostapd.pid /etc/hostapd/hostapd.conf
Configuration file: /etc/hostapd/hostapd.conf
Failed to create interface mon.wlan0: -95 (Operation not supported)
wlan0: Could not connect to kernel driver
Using interface wlan0 with hwaddr b8:27:eb:b1:68:9f and ssid "rgnet"
wlan0: interface state UNINITIALIZED->ENABLED
wlan0: AP-ENABLED 
```

Set hostapd to auto-start, though I am not sure that this is needed

```
update-rc.d hostapd enable
```