Dietpi: HowTo: Setup WiFi-Hotspot (AP) without Ethernet just for local subnetwork

[malakhovks]

How to setup Wifi-Hotspot (AP) without Ethernet just for local subnetwork?
When I am trying to setup AP via Dietpi-Software WiFi Hotspot: turn your device into a wifi hotspot it says that Ethernet test FAILED.
I see that is possible via manual installation and setting up as needed, but I don't find how to do that.

Required Information

• DietPi version

G_DIETPI_VERSION_CORE=6
G_DIETPI_VERSION_SUB=22
G_DIETPI_VERSION_RC=3
G_GITBRANCH=master
G_GITOWNER=Fourdee

• Distro version

DietPi_v6.17_NanoPiNEOAir-ARMv7-Stretch

• Kernel version

Linux DietPi 4.14.52 #19 SMP Thu Oct 11 11:33:51 CST 2018 armv7l GNU/Linux

• SBC device

NanoPi NEO Air (armv7l)
No Ethernet

• Power supply used

5V 2A

• SDcard used

 SanDisk ultra 16 gb

[malakhovks]

I took a bottle of red wine and solved the problem. Instructions for the owners of NanoPi NEO Air. Please add this somewhere in wiki or docs section.

Setting up NanoPi NEO Air as an access point in a standalone network without Ethernet on Dietpi OS

Use the following to update first:

$ apt-get update
$ apt-get upgrade

Install all the required software in one go with this command:

$ apt-get install dnsmasq hostapd dhcpcd5

Since the configuration files are not ready yet, turn the new software off as follows:

$ systemctl stop dnsmasq
$ systemctl stop hostapd

Configuring a static IP

We are configuring a standalone network to act as a server, so the Nanopi Neo Air needs to have a static IP address assigned to the wireless port. This documentation assumes that we are using the standard 192.168.x.x IP addresses for our wireless network, so we will assign the server the IP address 192.168.2.1. It is also assumed that the wireless device being used is wlan0.

To configure the static IP address, edit the dhcpcd configuration file with:

$ nano /etc/dhcpcd.conf

Go to the end of the file and edit it so that it looks like the following:

interface wlan0
    static ip_address=192.168.2.1/24

Now restart the dhcpcd daemon and set up the new wlan0 configuration:

$ service dhcpcd restart

Configuring the DHCP server (dnsmasq)

The DHCP service is provided by dnsmasq. By default, the configuration file contains a lot of information that is not needed, and it is easier to start from scratch. Rename this configuration file, and edit a new one:

$ mv /etc/dnsmasq.conf /etc/dnsmasq.conf.orig  
$ nano /etc/dnsmasq.conf

Type or copy the following information into the dnsmasq configuration file and save it:

interface=wlan0      # Use the require wireless interface - usually wlan0
  dhcp-range=192.168.2.2,192.168.2.20,255.255.255.0,24h

So for wlan0, we are going to provide IP addresses between 192.168.2.2 and 192.168.2.20, with a lease time of 24 hours. If you are providing DHCP services for other network devices (e.g. eth0), you could add more sections with the appropriate interface header, with the range of addresses you intend to provide to that interface.

There are many more options for dnsmasq; see the dnsmasq documentation for more details.

Configuring the access point host software (hostapd)

You need to edit the hostapd configuration file, located at /etc/hostapd/hostapd.conf, to add the various parameters for your wireless network. After initial install, this will be a new/empty file.

$ nano /etc/hostapd/hostapd.conf

Add the information below to the configuration file. This configuration assumes we are using channel 6, with a network name of dietpi, and a password 1234567890. Note that the name and password should not have quotes around them.

interface=wlan0
driver=nl80211
ssid=dietpi
hw_mode=g
channel=6
wmm_enabled=1 # QoS support
ieee80211n=1 # 802.11n support
macaddr_acl=0
auth_algs=1
ignore_broadcast_ssid=0
wpa=2
wpa_passphrase=1234567890
wpa_key_mgmt=WPA-PSK
#wpa_pairwise=TKIP CCMP # You better do not use this weak encryption (only used by old client devices)
rsn_pairwise=CCMP
ht_capab=[HT40][SHORT-GI-20][DSSS_CCK-40]

We now need to tell the system where to find this configuration file.

$ nano /etc/default/hostapd

Find the line with #DAEMON_CONF, and replace it with this:

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

INTERFACES

Since in the previous tutorial we set up the board to automatically connect to a network we must now adapt the file to its new behaviour.
/etc/network/interfaces

#CONNECT TO WIFI NETWORK
#auto wlan0
#allow-hotplug wlan0
#iface wlan0 inet dhcp
#wpa-conf /etc/wpa_supplicant/wpa_supplicant.conf
#iface default inet dhcp

#CREATE ACCESS POINT
auto wlan0
iface wlan0 inet static
  address 192.168.42.1
  netmask 255.255.255.0

#Local loopback
auto lo
iface lo inet loopback

Start it up

Now start up the remaining services:

$ service hostapd start  
$ service dnsmasq start
$ reboot

Connect to the dietpi network and SSH to 192.168.2.1

$ ssh [email protected]

[MichaIng]

@malakhovks
Great write-up. Jep indeed our WiFi Hotspot solution currently does not support local LAN-only setups. It is intended that you have an internet capable Ethernet beside so updates checks, installing packages etc still works and to assure there is always a left SSH way even if things break.

Just a little note:

• We use isc-dhcp-server for our Hotspot implementation.
• Major reason is that it works well with isc-dhcp-client which is mostly the default on Debian and allows to run and be started on a per-interface level via ifupdown hooks. It allows iface eth0 inet dhcp entries while dhcpcd requires iface eth0 inet manual, thus not so well integrated with ifupdown.
• But yeah in your case it doesn't matter at all and generally dhcpcd works perfectly well as client and server.

---

I turned this into a feature request as well, middle/long term we want to make our network setup (DietPi-Config) more flexible and compatible with custom settings/needs.

[diveyez]

Just use this instead https://github.com/garywill/linux-router

[malakhovks]

Just use this instead https://github.com/garywill/linux-router

I tried this option, it does not work for my setup with NanoPi NEO Air (armv7l) and No Ethernet :

root@DietPi:~/linux-router# ./lnxrouter -n --ap wlan0 dietpi --password 1234567890q
WARN: brmfmac driver doesn't work properly with virtual interfaces and
      it can cause kernel panic. For this reason we disallow virtual
      interfaces for your adapter.
      For more info: https://github.com/oblique/create_ap/issues/203
ERROR: Your adapter can not be a station (i.e. be connected) and an AP at the same time

[diveyez]

You can use two WiFi adapters....

[malakhovks]

So, maybe any new suggestions ?

[diveyez]

Purchase the needed adapter.....

[MichaIng]

@malakhovks
Hmm it looks like linux-router also expects a second interface, or it just fails if the WiFi interface is still up, connected to another AP 🤔. You need to take care at least first that WiFi is completely down:
ifdown wlan0
And in /etc/network/interfaces comment all wlan0/WiFi related lines (the thirst block). Then retry to apply lnxrouter.

Ah sorry, forgot that NanoPi NEO Air does not have HDMI, so you are not able to disable the WiFi interface, otherwise SSH would be down, so you cannot go on with any other connection. Even if you go with some trick (enable AP only in /etc/network/interfaces but not apply it yet, keeping WiFi up, then reboot to apply changes), if anything with that fails, you would not be able to ever connect to the NanoPi again.

Only safe possibility is if you had a serial terminal to access via serial console. Then the above out-crossed hint could be tried.

[Joulinar]

Just for the record @MichaIng

Another way how to setup Hotspot/AP if you like to use simultaneous AP and Managed Mode Wifi same time on a SBC that don't have eth0 interface.

https://dietpi.com/phpbb/viewtopic.php?f=9&t=7828

[MichaIng]

Totally makes sense. I already started to work on the new network setup, however lack of time and some other urgent topics prevented me from finishing it. Next regular release will definitely contain it!