On 11/03/2019 13:23, Mouse wrote:
What I struggle to tell, regardles of OS, is if a device is physical or virtual (such as PPP, TAP or TUN).Why do you care? I'm having trouble thinking of a reason to care, and, actually, I'm not sure you _should_ be able to tell. Indeed, the concept we usually think of as a network interface is a virtualization, provided (by the driver and some pieces of MI kernel) atop the actual hardware.
Generally you would want all physical interfaces to autoconfigure (ie DHCP, RA, etc).
This is rarely true for virtual interfaces.On the flip side, you generally want to prefer DNS from a virtual interface (like say a VPN) when connected over a more general DNS such as from wired ethernet. So when you goto mouse.rejects.email.blah and it can resolve to a private IP (over VPN) or a public IP (over eth0) it will use the VPN.
Running dhcpcd on all interfaces (for example) won't break anything, but equally it's a waste of potential resources.
Also, I could argue whether ppp is virtual or not; it seems to me it's a defensible position that ppp, at least when connected to a real serial port, is as real an interface as any Ethernet, just using (very) different layers 1 and 2.
When my serial ports are listed by ifconfig after booting single user I would agree they wouldn't be virtual.
But they are not, so they are virtual. Roy