====== /etc/network/interfaces ======

The reference documents for this Debian configuration file are:

  * **''man 5 interfaces''**
  * **''man wireless''**
  * **''man resolvconf''** for ''resolvconf'' options (''dns-nameservers'', ''dns-search'', etc.)
  * **''/usr/share/doc/wireless-tools/README.Debian''**
  * **''/usr/share/doc/wpasupplicant/README.Debian.gz''** for wpa- options
===== Examples =====

==== WiFi interfaces with WPA ====

See this two pages: [[http://wiki.debian.org/WPA#wpa_supplicant_in_Debian_6.0_.28Squeeze.29|wpa_supplicant in Debian 6.0]] and [[http://wiki.debian.org/WiFi/HowToUse#wpasupplicant|How To Use wpasupplicant]].

**Automatic IP address and WPA security** (credential can be in the same file, or in ''wpa_supplicant.conf'':

<file>
allow-hotplug wlan0
iface wlan0 inet dhcp
    #wpa-ssid MyESSID
    #wpa-psk MyWPASecret
    wpa-conf /etc/wpa_supplicant/wpa_supplicant.conf
</file>

**Static IP address with WPA security**; with this configuration the WiFi connection will be not managed by NetworkManager:

<file>
auto wlan0
iface wlan0 inet static
        address 10.0.0.166
        netmask 255.255.255.0
        gateway 10.0.0.189
        dns-nameservers 62.48.51.6 151.99.125.2
        #wpa-ssid MyESSID
        #wpa-psk MyWPASecret
        wpa-conf /etc/wpa_supplicant/wpa_supplicant.conf
</file>

**Static IP address, without encryption**:

<file>
auto eth1
iface eth1 inet static
        address 192.168.0.191
        netmask 255.255.255.0
        gateway 192.168.0.249
        dns-nameservers 62.48.51.6 8.8.8.8
        wireless-essid MyESSID
        wireless-mode Managed
        wireless-key off
</file>

==== Static address, not managed by NetworkManager ====

Debian (9 Stretch) installs the **network-manager** package, which handles the configuration of Ethernet interface automatically, via DHCP. If you want to manually configure the interface, just put this in **/etc/network/interfaces** configuration file:

<file>
allow-hotplug enp2s0
iface enp2s0 inet static
        address 10.0.1.2
        netmask 255.255.255.0
        gateway 10.0.1.252
        dns-nameservers 144.76.67.15 8.8.8.8
</file>

You need the **resolvconf** package to make the //dns-nameservers// option working. That option adds the **nameserver** line into the **/etc/resolv.conf** file at boot time.