ifconfig(8) vs. iproute

[Cross-posting to and setting
Followup-To: there.]

... Isn't ifconfig considered obsolete these days, in favor of
the almighty ip(8)? And, FWIW, ip(8) doesn't seem to contain
the word "alias." (And neither does its output; see below.)

AIUI, initially, Linux (the kernel) allowed just one IPv4
address per interface. Thus, the notion of "aliases" -- several
"logical" network interface per single "physical" one -- was
introduced. With the kernel's IP implementation extended to
handle the case in an (arguably) better and more logical
fashion, the very notion of an "interface alias" became
obsolete. (And, as was already noted in this thread, these
weren't "first-class" interfaces to begin with; for instance, I
doubt that one'd use such an "alias" in the route(8) command.)

$ ip addr list
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: eth5: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN qlen 1000
link/ether f0:12:34:56:78:9a brd ff:ff:ff:ff:ff:ff
inet 192.0.2.34/24 brd 192.0.2.255 scope global eth5
inet6 2001:db8:1337::cafe/64 scope global
valid_lft forever preferred_lft forever
inet6 2001:db8:2001::da:42/64 scope global
valid_lft forever preferred_lft forever
....
$

[...]

 

Some people claim it is. What it boils down to is whether the people
who maintain ifconfig are dedicated to improve and extend it over
time, or if they just keep it running.

ip(8) /is/ IME more aligned with today's Linux networking support than
ifconfig, route and the rest of net-tools (the name of the Debian
package). A bit unfortunate -- almost everyone I know use the latter
tools by habit, and so they miss out on features.

/Jorgen