How to setup multiple WiFi networks?

Question

I go back and forth from home to school with my Pi. I just got the WiFi working last night at home using wpa.conf instead of wpa_supplicant.conf as the book I was using had the walk thru for that instead. I've noticed lots seem to use wpa_supplicant but I not sure why...

Anyway, I know how to make the WiFi IP static for my home network but how do I set things up for auto-connecting to my school WiFi and use a different static IP for that network?

For the network do I just add another network={} in my wpa.conf file? For the second static IP how do I bind that to the school network?

Answer 1

Edit /etc/wpa_supplicant/wpa_supplicant.conf and add id_str="school" under the schools wpa info and id_str="home" under your homes wpa info. Your file should now look similar to this:

ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
update_config=1

network={
    ssid="SCHOOLS NETWORK NAME"
    psk="SCHOOLS PASSWORD"
    id_str="school"
}

network={
    ssid="HOME NETWORK NAME"
    psk="HOME PASSWORD"
    id_str="home"
}

Then set up /etc/network/interfaces with iface school inet static and iface home inet static in it so it looks like the following:

This applies to Raspbian Wheezy prior to 2015-05-05 for later (and Jessie) See How do I set up networking/WiFi/Static IP

auto lo

iface lo inet loopback
iface eth0 inet dhcp

allow-hotplug wlan0
iface wlan0 inet manual
wpa-roam /etc/wpa_supplicant/wpa_supplicant.conf

iface school inet static
address <school address>
gateway <school gateway>
netmask <school netmask>

iface home inet static
address <home address>
gateway <home gateway>
netmask <home netmask>

Answer 2

With Raspbian Jessie release, you don't have to edit the interface file. Just updating the wpa_supplicant file with multiple networks would suffice. Here's how it looks -

ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
update_config=1

network={
    ssid="SCHOOLS NETWORK NAME"
    psk="SCHOOLS PASSWORD"
    id_str="school"
}

network={
    ssid="HOME NETWORK NAME"
    psk="HOME PASSWORD"
    id_str="home"
}

This worked for me and my wifi is always connected to the list of available networks mentioned in the above file. Hope it helps.

Answer 3

I recently stumbled across a console application that sorts all the wireless configuration hell out. You can also use this tool to configure the LAN interface.

sudo apt-get install wicd-curses

It will install quite a few other packages but it runs its own daemon in the background. This manages the networks and makes sure you connect to the ones you want. Run it with:

sudo wicd-curses

If you get a message saying no networks detected press P (must be capital so use [SHIFT]p) and type in wlan0 in the wireless interface field and press F10 to save.

1. R to refresh the list.
2. Use the cursors on the keyboard to navigate up and down the list
3. Press right to configure the wireless connection
4. Press down a few times and check "Automatically connect to this network"
5. Press down a few times again and type in your password in the key field
6. Press F10 to save
7. Start from 1 to do this again for any other networks

You might have to press C to connect to the access point. If you were connected via cable, that will most likely kill the LAN interface and bring up wireless.

It is also manages the connection so it will reconnect to any configured wireless access points if it drops out for whatever reason but it will also try to connect to any available networks, just like in Windows, Macintosh or Linux Desktops.

Hope it helps!

Answer 4

Actually you can add the priority option. Like so:

network={
      ssid="open"
      key_mgmt=NONE
      id_str="open"
      priority=3
}

network={
        ssid="secure"
        key_mgmt=WPA-EAP
        proto=WPA2
        group=CCMP
        pairwise=CCMP
        eap=TLS
        ca_cert="/etc/certs/cacert.pem"
        client_cert="/etc/certs/client.pem"
        private_key="/etc/certs/client.key"
        private_key_passwd="somepwd"
        identity="me"
        priority=5
}

network={
        ssid="AndroidAP"
        key_mgmt=WPA-PSK
        proto=WPA2
        pairwise=CCMP
        group=CCMP
        psk="SomeP4ssw0rd"
        priority=4
}


network={
        ssid="Spooky"
        key_mgmt=NONE
        group=WEP104
        psk="A4ABC2FC27412D4D23CAEBCA23"
        priority=2
}

network={
        ssid="another"
        key_mgmt=WPA-PSK
        proto=WPA2
        pairwise=CCMP
        group=CCMP
        psk="A very long and secret passphrase here"
        priority=1
}

priority: when multiple networks are available simultaneously, the one with the highest priority value is selected.

id_str: for each network, you can give this parameter a specific value (a string). If none is provided, "default" is used as text string. This string is used in /etc/network/interfaces as a virtual interface identifier. This allow creating specific configuration blocks for each network. The only requirement is to have the physical interface using the "inet manual" method (this is a MUST).