Subject: Re: mutating IPv4 aliases on NetBSD 2 systems
To: None <tech-net@NetBSD.org>
From: None <joerg@britannica.bec.de>
List: tech-net
Date: 02/24/2006 17:02:43
On Fri, Feb 24, 2006 at 09:57:03AM -0500, der Mouse wrote:
> > The kernel doesn't really have a concept of "aliases", just multiple
> > addresses on an interface.
> 
> But the first one on the list *is* special in a few ways (for example,
> it's the one that gets replaced if you ifconfig an address on the
> interface without saying "alias", and it's the one that gets used as
> the source address of source-not-specified traffic going out that
> interface).

Well, ifconfig indead works on the first address by default.
The source address is determined by the routing table, I think. The same
rule applies there -- first rule wins. /32 addresses should never be
used by default, not sure why it does pickup the corresponding broad
cast address though. I think wol(1) should walk the address list and
notify all broadcast addresses on the interface, since e.g. two
distinguished networks can be configured on it.

Joerg