On 02/11/2023 00:44, tomas@tuxteam.de wrote:
On Wed, Nov 01, 2023 at 10:00:45PM +0700, Max Nikulin wrote:Doesn't allow-hotplug means adding a network adapter (e.g. a USB one), not plugging network cable into an existing adapter (built-in or connected earlier)?Following the man page (interfaces (5)) you are right, of course. In theory, however, since things are kicked off by an udev rule (i.e. udev calling some command) it shouldn't be too hard (TM) to wire up things, provided you've a monitor which tells you when an eth has carrier.
I am unsure if it is exposed as a udev event or it is necessary to receive messages from netlink socket. Anyway it is already implemented in NetworkManager and it allows to get a DHCP lease immediately when cable is plugged. On the other hand it is possible to uncheck connection.autoconnect to make NetworkManager waiting for an explicit user action, either a couple of mouse clicks or a command in terminal, to activate a particular connection.
I am a bit surprised by a use case when temporary unplugging of cable should be ignored. I have not tested it, but I hope, a setting, I have noticed in docs, allows NetworkManager to handle it as well.