On Wed, Feb 13, 2019 at 8:10 AM Greg Wooledge <wool...@eeg.ccf.org> wrote:
> On Tue, Feb 12, 2019 at 10:49:13PM -0600, Kent West wrote:
> > "The Debian Administrator's Handbook" is for version 8, and talks
> > about deprecated tools like ifup/down, which aren't even installed by
> > default on stretch.
>
> The ifupdown package has priority "important" and, as far as I know, it
> is installed by default.
>
> You might be confusing it with "ifconfig", which is in the net-tools
> package, which is *not* installed by default in stretch (a departure from
> previous releases).
>
"ifupdown" is indeed installed:
root@server-1:~# apt list ifupdown
Listing... Done
ifupdown/stable,now 0.8.19 amd64 [installed]
So you're right; I must've been confusing that package with "ifconfig".
> > But in trying to convert to a static address (by editing
> > /etc/network/interfaces), and then try to restart the network ("ip link
> set
> > dev enp0s3 down", then "...up")
>
> OK, let's back up a second.
>
> What was in the /etc/network/interfaces file *before* you edited it? Was
> it configured for DHCP? If so, you should bring the interface down
> *before*
> you edit the file, so that ifdown knows there is a DHCP client daemon
> running associated with this interface, that it should kill.
>
If you're currently configured for DHCP, and you edit the file before
> bringing down the interface, the DHCP client daemon will continue running
> (ifdown doesn't know about it, because you changed the file that would
> have told it). Which means you would have to kill the DHCP client daemon
> yourself, either manually, or by rebooting.
>
I think this must've been my problem; I must've edited the interfaces file
before downing the interface, which confused the system. It works as
expected when I do it in the sequence you present below:
> So, the proper sequence is:
>
> 1) ifdown interfacename
> 2) edit /etc/network/interfaces
> 3) ifup interfacename
>
> What's in the /etc/network/interfaces file now?
>
roo@server-1:~# cat /etc/network/interfaces
# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).
source /etc/network/interfaces.d/*
# The loopback network interface
auto lo
iface lo inet loopback
# The primary network interface
allow-hotplug enp0s31f6
iface enp0s31f6 inet dhcp
But, as mentioned, if I "ifdown enp0s3", then make the above change, then
"ifup enpos3", I have working network. So this method you provide works;
thanks! (The other troubleshooting questions you asked, I'm bypassing, as
the basic problem has been solved.)
But, that leaves my second question unanswered:
2) What is the canonical current method in 2019 to [semi-]manually
configure networking in stretch? And is it documented anywhere? (My two
days of searching leads me to think "no". Or my google-fu really sucks.)
I *thought* "/etc/network/interfaces" was being phased out (perhaps as part
of systemd or Network-Manager?). Then the web provides this answer then
that answer - "service...", "systemctl...", "ip...", "ifup...", "if up...",
and I'm confident some of these are deprecated or not preferred or apply in
Case X but not Case Y, etc. With "The Handbook" being out of date, is there
a definitive explanation/guide out there?
Again, thanks for getting me beyond my snag!
--
Kent West <")))><
Westing Peacefully - http://kentwest.blogspot.com
