Mon cheri > Sent: Sunday, March 20, 2022 at 10:31 PM > From: "David Wright" <deb...@lionunicorn.co.uk> > To: debian-user@lists.debian.org > Subject: Re: Under each of these scenarios, what is the neatest and simplest > way to manipulate the /etc/network/interfaces file? > > On Sat 19 Mar 2022 at 03:14:54 (+0100), Stella Ashburne wrote: > > > > There are instances in which my machine is connected to a mobile hotspot. > > And in some situations, it's connected to a smartphone via USB tethering. > > And when I'm in the office, I may connect it to a LAN cable. > > > > Below are the contents of my /etc/network/interfaces file: > > > > # 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/* > > I would change this line to > > source-directory /etc/network/interfaces.d > On Debian 11, the line
source /etc/network/interfaces.d/* is correct. > > I would then hive off all your interface configurations into > separate files in the directory /etc/network/interfaces.d > using all-ASCII filenames constructed from upper/lower-case > letters, digits, underscores, and minus-hyphens, as specified > on the man page, but with the string ".hidden" added to the end, > thus: > > myphone-tethered.hidden > office-wired.hidden > wifi.hidden > hotspot.hidden > > and so on. Files with a dot are ignored when included by means of > a source-directory directive. > On Debian 11, files with a dot are NOT ignored when the line source /etc/network/interfaces.d/* is present in /etc/network/interfaces I have tried the following: Attempt #1 When the files have the dot in /etc/network/interfaces.d/*, e.g. lan.hidden usb0.hidden wlo1.hidden username@hostname:~$ ip a 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft forever 2: wlo1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000 link/ether e5:d3:a2:b9:c3:27 brd ff:ff:ff:ff:ff:ff altname wln0s7 inet 192.168.43.51/24 brd 192.168.43.255 scope global dynamic wlo1 valid_lft 3588sec preferred_lft 3588sec username@hostname:~$ Attempt #2 When the files do NOT have the dot in /etc/network/interfaces.d/*, e.g. lan usb0 wlo1 username@hostname:~$ ip a 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft forever 2: wlo1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000 link/ether e5:d3:a2:b9:c3:27 brd ff:ff:ff:ff:ff:ff altname wln0s7 inet 192.168.43.51/24 brd 192.168.43.255 scope global dynamic wlo1 valid_lft 3576sec preferred_lft 3576sec username@hostname:~$ Summary: On Debian 11, files in /etc/network/interfaces.d/* do NOT require a DOT. Best regards. Stella