:: Re: [DNG] if2mac init.d service for…
Etusivu
Poista viesti
Vastaa
Lähettäjä: tito
Päiväys:  
Vastaanottaja: dng
Aihe: Re: [DNG] if2mac init.d service for persistent network interface names
On Thu, 24 Dec 2020 21:11:49 -0500
Steve Litt <slitt@???> wrote:

> On Thu, 24 Dec 2020 16:32:18 +0100
> tito via Dng <dng@???> wrote:
>
> > On Thu, 24 Dec 2020 10:10:07 -0500
> > Steve Litt <slitt@???> wrote:
> >
> > > On Wed, 23 Dec 2020 23:41:58 +0100
> > > Didier Kryn <kryn@???> wrote:
> > >
> > > > Le 23/12/2020 à 22:03, Antony Stone a écrit :  
> > > > > If the kernel decides A=eth1, B=eth2, C=eth0 then there's no
> > > > > way for udev rules to rename them, because "File
> > > > > exists" (which should of course say "Device name exists").    

> > > >
> > > >     This should not happen and did not happen in the past
> > > > because the interfaces are created sequentially.
> > >
> > > Yes it did. It happened in the 1900's. We were all advised never
> > > to use the same type of network card for both interfaces, because
> > > which card became eth0 would be indeterminate. I had eth0
> > > magically switch to eth1, and then back again, several times.
> > >
> > > Earlier in this thread I submitted a shellscript that fixes this
> > > whole problem, without all sorts of udev raindances.
> > >
> > > SteveT
> > >
> > > Steve Litt
> >
> > Hi,
> > is it this one? How does it solve my problem to rename
> > interfaces according to their mac address without
> > name collisions (plus corner cases)?
> >
> > #!/bin/sh
> > # Copyright (c) 2016 by Steve Litt
> > # Expat license. See http://directory.fsf.org/wiki/License:Expat
> >
> > chosen_wifi_number=${1:-1}
> > wifidevs=0
> >
> > for dev in `ip -o link | sed -n 's/[^:]*: *\(w[^:]*\).*/\1/p'`;
> > do
> >     wifidevs=`expr $wifidevs + 1`

> >
> >     test $wifidevs -eq $chosen_wifi_number && {
> >     echo $dev
> >     exit 0
> >     }
> > done

> >
> > echo =max$wifidevs
> >
> > Ciao,
> > Tito
>
>
> It either is the one, or looks a whole lot like it.
>
> Note that somebody else on this list made it even better, but I can't
> find that email again.
>
> If the "w" in the sed command is changed to "e", then it does the same
> thing for wired Ether net.
>
> The shellscript I wrote spits out one answer. However, it could easily
> be modified to do several, either letting you choose, or perhaps if
> running exec'ed or dotted, create environment vars like eth0, eth1,
> eth2, etc, and wlan0, wlan1, wlan2, etc, so all you need to do in your
> shellscripts is change "wlan0" to "$wlan0". As long as nobody switches
> slots or jacks, the numbering of these will be determinate.
>
> SteveT
>
> Steve Litt

Hi,
What I've experienced is that is that even pci bus numbers change from
one reboot to the other so unless you tie the names to the mac address
they will not be determinate and my router will not work at best and
lock me out in the worst case. On a desktop with 1-2 nics or 1 wifi
this is not that big problem as the names will stay mostly the same
just due to the low numbers involved.

Ciao,
Tito