From owner-freebsd-questions Tue Jun 24 01:11:33 1997 Return-Path: Received: (from root@localhost) by hub.freebsd.org (8.8.5/8.8.5) id BAA01879 for questions-outgoing; Tue, 24 Jun 1997 01:11:33 -0700 (PDT) Received: from gatekeeper.barcode.co.il (gatekeeper.barcode.co.il [192.116.93.17]) by hub.freebsd.org (8.8.5/8.8.5) with ESMTP id BAA01855 for ; Tue, 24 Jun 1997 01:11:28 -0700 (PDT) Received: (from smap@localhost) by gatekeeper.barcode.co.il (8.8.5/8.6.12) id LAA08931; Tue, 24 Jun 1997 11:11:04 +0300 (IDT) X-Authentication-Warning: gatekeeper.barcode.co.il: smap set sender to using -f Received: from localhost.barcode.co.il(127.0.0.1) by gatekeeper.barcode.co.il via smap (V1.3) id sma008929; Tue Jun 24 11:10:41 1997 Message-ID: <33AF80C4.75C0@barcode.co.il> Date: Tue, 24 Jun 1997 11:09:40 +0300 From: Nadav Eiron X-Mailer: Mozilla 3.0 (X11; I; SunOS 5.5 sun4m) MIME-Version: 1.0 To: John-David Childs CC: freebsd-questions@FreeBSD.ORG Subject: Re: IP aliasing on lo0 or ethernet? References: Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-questions@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk John-David Childs wrote: > > While looking through the handbook for info about CVSUP, I came across > three "tutorials" on IP aliasing (one in the Handbook, one in the FAQ, and > one in the "Tutorials"). All three basically suggested IP aliasing to the > Ethernet card, using netmask 255.255.255.255 and adding route commands to > route the aliased IP to the loopback device. > > However, for several years now I've been aliasing IP's to the loopback > device directly, and using arp commands to distribute the aliased IP to > routing daemons in the subnet if necessary. > > So, why is aliasing to the ethernet device preferable to aliasing to lo0? > Or more accurately stated...what's the difference and why would one choose > method A over method B? Thanks for the advice. By what I recall, specifying a netmask of all 1's will even do the routing automatically, so you have nothing to do except for the ifconfig itself. Aliasing the loopback and manually arping seems crude and ugly to me... After all what you'd like is for your Ethernet interface to have more than one address, it's not a loopback address you're interested in... > -- > > John-David Childs (JC612) @denver.net/Internet-Coach > System Administrator Enterprise Internet Solutions > & Network Engineer 901 E 17th Ave, Denver 80218 > "I used up all my sick days... so I'm calling in dead!" Nadav