On Sun, Oct 12, 2025 at 07:05:22AM -0700, Peter via Dng wrote:

> From:    Ralph Ronnquist via Dng <dng@???>
> Date:    Wed, 10 Sep 2025 09:59:19 +1000
> > The "ip xxx" suite of commands are available and sometimes useful when
> > you need to manipulate network settings in unusual ways especially
> > with distinction between the link and network levels. But that only
> > does the work of ifconfig. The ifupdown program collection implements
> > a concept structure for the transport level configuration and would if
> > anything compete with tools like network-manager.

>
> "ip link set <interface> up" is equivalent to "ifup <interface>"?

No. An interface has a "link level" and a "network level".

`ip link set $iface up` brings it upat link level

`ip address add $address/$bits dev $iface` brings it up at network
level, which requires it up at link level


`ifup $iface` uses /etc/network/interfaces to raise $iface as
specified, which typically is network level.

>
> Can ifup do something which ip can not do?

`ifup` can do anything if there are "up" directives for it; it's
higher level networking really. But any interface related actions are
avialable to be done with `ip`.

>
> Is the line beginning "ifup" in the table here incorrect?
> https://en.wikipedia.org/wiki/Iproute2

No.

Ralph.