Re: LANANA: To Pending Device Number Registrants

Andrew Morton
2001-05-16T02:35:12Z

Jonathan Lundell wrote:
>
> ...
> I *like* eth0..n (I'd like net0..n better). And I *can't* ask what
> eth0 and eth1 are, by the way, but I should be able to (Jeff Garzik
> has proposed an extension to ethtool to help out this lack, but it's
> not in Linux today, and needs concrete implementation anyway).
>
> But that's not my point. I'm *not* proposing that we exchange eth0
> for geographic names. I'm suggesting, though, that the location of
> the device is *not* meaningless, because it's the physically-located
> RJ45 socket (or whatever) that I have to connect a particular cable
> to. Sure, no big deal for systems with a single connection, but it
> becomes a real pain when you've got a dozen, which is a reasonable
> number for some network-infrastructure functions (eg firewalls).
>
> When I ifconfig one of a collection of interfaces, I'm very much
> talking about the specific physical interface connected via a
> specific physical cable to a specific physical switch port.
>

Yes, it can be a security trap as well - physically move a card and
your firewall rules end up being applied to the wrong connection.

The 2.4 kernel allows you to rename an interface. So you can build
a little database of (MAC address/name) pairs. Apply this after booting
and before bringing up the interfaces and everything has the name
you wanted, based on MAC address.

Andi Kleen has an app which does this:

ftp://ftp.firstfloor.org/pub/ak/smallsrc/nameif.c

but apparently some additional kernel work is needed to make
this work 100% correctly. I do not know what the specific
problem is.

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