Subject: Re: "default" outgoing address
To: None <tech-kern@netbsd.org>
From: Paul A Vixie <paul@vix.com>
List: tech-kern
Date: 02/04/1999 15:10:29
> then...ifconfig the flame.org address first as the real address and
> then add the vix.com address as the alias.

that's not an option, for two reasons.

1. when you have multiple physical interfaces, as with a gateway or firewall,
you still want the default source address of all of your tcp connections to
be the one true lo0 alias by which ospf and kerberos know you.

2. the alias is not lan-specific.  it's not part of any subnet.  it's portable.
(i have, using a UPS, moved a host from one building and network to another
building and network, without losing open tcp sessions.)  you can't arp these.