What's the default /etc/network/interfaces?

Question

I messed up my network configuration. Can anyone help me and copy the default /etc/network/interfaces?

More about loopback : http://askubuntu.com/questions/247625/what-is-the-loopback-device-and-how-do-i-use-it — find_x, Oct 25 '15 at 20:37

score 40 · Accepted Answer · answered Nov 07 '12 at 16:13

40

For eth0 with dhcp:

# The loopback network interface
auto lo eth0
iface lo inet loopback

# The primary network interface
iface eth0 inet dhcp

For eth0 static:

# The loopback network interface
auto lo eth0
iface lo inet loopback

# The primary network interface
iface eth0 inet static
    address 192.168.10.33
    netmask 255.255.255.0
    broadcast 192.168.10.255
    network 192.168.10.0
    gateway 192.168.10.254 
dns-nameservers 192.168.10.254

link: http://www.iasptk.com/ubuntu/20202-ubuntu-server-networking-configuration-dhcp-address-static-ip-address-second-ip-address-or-virtual-ip-address

answered Nov 07 '12 at 16:13

ptheo

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So what do I do if mine has no primary network interface, just has iface lo inet loopback ?? – IgorGanapolsky Mar 31 '15 at 18:42
You have to add a primary (dhcp OR static) adding the lines above – ptheo Apr 01 '15 at 19:04
What if I don't add 'network' and 'broadcast' entries? Will the default to the reasonable values? – JohnyTex Sep 27 '18 at 09:12
As reference, this answer shows [how to find the network device name](https://askubuntu.com/a/976282/625092) - as `eth0` is no longer that common. – S3DEV Jul 31 '23 at 09:36

score 14 · Answer 2 · answered Nov 07 '12 at 15:53

14

Mine looks like:

auto lo
iface lo inet loopback

answered Nov 07 '12 at 15:53

Wolf F.

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score 6 · Answer 3 · edited Apr 08 '14 at 14:17

6

Following the Debian network configuration page, if you're just using DHCP then all you need is something like:

auto eth0
allow-hotplug eth0
iface eth0 inet dhcp

edited Apr 08 '14 at 14:17

Luís de Sousa

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answered Apr 08 '14 at 13:42

Yoga

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score 0 · Answer 4 · edited Jan 08 '22 at 04:06

0

Here are the default contents of /etc/network/interfaces:

# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).
source /etc/network/interfaces.d/*
# The loopback network interface
auto lo
iface lo inet loopback

edited Jan 08 '22 at 04:06

Error404

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answered Jan 04 '22 at 07:26

Bercove

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What's the default /etc/network/interfaces?

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