From owner-freebsd-questions  Thu Apr 25 04:11:14 1996
Return-Path: owner-questions
Received: (from root@localhost)
          by freefall.freebsd.org (8.7.3/8.7.3) id EAA02168
          for questions-outgoing; Thu, 25 Apr 1996 04:11:14 -0700 (PDT)
Received: from apollo.is.co.za (apollo.is.co.za [196.4.160.2])
          by freefall.freebsd.org (8.7.3/8.7.3) with ESMTP id EAA02161
          for <questions@freebsd.org>; Thu, 25 Apr 1996 04:11:10 -0700 (PDT)
Received: from admin.is.co.za (admin.is.co.za [196.23.0.9]) by apollo.is.co.za (8.7.5/8.7.5/IShub#2) with ESMTP id NAA14704; Thu, 25 Apr 1996 13:10:53 +0200 (GMT)
Received: (from robin@localhost) by admin.is.co.za (8.7.5/8.7.5/ISsubsidiary#1) id NAA18815; Thu, 25 Apr 1996 13:10:52 +0200 (GMT)
From: Robin Lunn <robin@is.co.za>
Message-Id: <199604251110.NAA18815@admin.is.co.za>
Subject: Re: 2 differents IP on the same interface ?
To: Eric.Berenguier@sycomore.fr (Eric Berenguier)
Date: Thu, 25 Apr 1996 13:10:51 +0200 (GMT)
Cc: questions@freebsd.org
In-Reply-To: <v01530502ada4fe7e0f65@[192.134.92.34]> from "Eric Berenguier" at Apr 25, 96 12:12:46 pm
X-Organisation: The Internet Solution (Pty) Ltd.
X-Phone: +27-11-4475566; Fax: +27-11-4475567
Reply-To: robin@is.co.za
X-AIDAT-Member: See http://www.aidat.org
X-Mailer: ELM [version 2.4 PL23]
Content-Type: text
Sender: owner-questions@freebsd.org
X-Loop: FreeBSD.org
Precedence: bulk

Eric Berenguier wrote:
>         Is it possible to give several adresses to a single network
> interface on a FreeBSD system ?
>         (I know it's possible to do this with latest Linux kernel (IP_ALIAS))

I have no idea how this might be done with ppp or slip, but on ethernet the
following:

ifconfig <device> alias <ip alias>
route add <ip alias> 127.0.0.1

Lazy way to make this permanent: Add these commands to /etc/rc.local

More scalable way to permanency:
Add the following to /etc/sysconfig: (put them with like config options)
--
# network interface aliases
interface_aliases="ed1"
alias_ed1="alias x.x.x.x"
route_alias1="x.x.x.x 127.0.0.1"
--
Add the word alias1 to the static_routes= definition.
Add the following to /etc/netstart:
--
# Set up any aliases to network interfaces.
for device in ${interface_aliases}; do
        eval ifconfig_args=\$alias_${device}
        ifconfig ${device} ${ifconfig_args}
done
--
This way if you have more than one alias on an interface you just have:
alias_ed1="alias x.x.x.x alias y.y.y.y alias z.z.z.z"
route_alias1="x.x.x.x 127.0.0.1"
route_alias2="y.y.y.y 127.0.0.1"
route_alias3="z.z.z.z 127.0.0.1"
static_routes="multicast alias1 alias2 alias3 loopback"

All of your network config info is still in one file this way and you can
easily see the aliases assigned to an interface.
-- 
_ __                  | Only my ideas here unless I say otherwise...
' )  )     /          | (BeamJack@IRC)                 
 /--' ____/___o  __   | "Nondum amabam, et amare amabam...  quaerebam quid
/  \_(_) /_) (__/) )_ |  amarem, amans amare." - St Augustine