ifup will only call ifconfig if the interface is statically configured - see line 3924 of ifupdown.nw. If it's using dhcp, then dhclient will do that. There's never been any requirement for an interface to be up before dhclient is run on it.
ifup will only call ifconfig if the interface is statically configured - see line 3924 of ifupdown.nw. If it's using dhcp, then dhclient will do that. There's never been any requirement for an interface to be up before dhclient is run on it.