[gnosek]

    ifconfig enp2s0:1 192.168.1.42

Now try

    ip addr add dev enp2s0 192.168.42.1/24

and observe how ifconfig ignores the second IP on the same interface. enp2s0:1 is an alias to enp2s0, not enp2s0 itself. To replicate your ifconfig command, you'd use

    ip addr add dev enp2s0 192.168.1.42/32 label enp2s0:1

and then it shows up in ifconfig as well.

[simias]

You're right, it's not exactly the same thing and both approaches (with an alias and without) have their uses. ifconfig forcing you to come up with a unique label can be annoying when you want some script to add a new address to an interface without having to go handle the error case of "but what if <iface>:1 is already used?".

Meanwhile having an explicit label can be nice in other situations if you want to replace an address instead of merely adding a new one.

I also seem to recall running into issues dealing with IPv6 with ifconfig that I worked around by switching to ip. I don't remember the specifics however.

Overall I wish ifconfig had been updated, I still find it a lot more user friendly that iproute. In particular the default output of a plain "ifconfig" is vastly more readable IMO: https://svkt.org/~simias/up/20200319-165513_ip.png

In general these days I use ip in scripts and ifconfig (when available) interactively. I don't love having to remember two ways of doing the same thing but I can't rely on ifconfig being available in scripts anymore and I just waste too much time parsing ip's bad output when I'm messing with networking interactively.

[squarefoot]

Understood, thanks, I'm so used to ifconfig that always tried to avoid using ip. Time to learn it I guess.

[gerdesj]

I spend a lot of times dealing with new devices. Plug it into the same VLAN as my desktop and then in a term:

# ip a a 192.168.1.32/24 dev eth0

Then put 192.168.1.1 into browser etc. Do job. Back to term. Up arrow to get last command, change the second a to d (for delete) and the extra address is gone.