From owner-freebsd-questions@FreeBSD.ORG Tue Jan 31 10:23:47 2006 Return-Path: X-Original-To: freebsd-questions@freebsd.org Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 1FF4A16A424 for ; Tue, 31 Jan 2006 10:23:47 +0000 (GMT) (envelope-from tomasflyer@netscape.net) Received: from imo-d02.mx.aol.com (imo-d02.mx.aol.com [205.188.157.34]) by mx1.FreeBSD.org (Postfix) with ESMTP id 9A48D43D48 for ; Tue, 31 Jan 2006 10:23:46 +0000 (GMT) (envelope-from tomasflyer@netscape.net) Received: from tomasflyer@netscape.net by imo-d02.mx.aol.com (mail_out_v38_r6.3.) id n.1b2.10b7224b (22681) for ; Tue, 31 Jan 2006 05:23:39 -0500 (EST) Received: from mblkn-m01 (mblkn-m01.mblk.aol.com [64.12.170.65]) by air-in04.mx.aol.com (v108_r1_b1.2) with ESMTP id MAILININ42-589943df3aab3e6; Tue, 31 Jan 2006 05:23:39 -0500 Content-Transfer-Encoding: quoted-printable Date: Tue, 31 Jan 2006 05:23:39 -0500 From: tomasflyer@netscape.net Message-Id: <8C7F4678970ACD2-1EFC-9D50@mblkn-m01.sysops.aol.com> X-MB-Message-Source: WebUI X-MB-Message-Type: User Received: from 194.237.142.10 by mblkn-m01.sysops.aol.com (64.12.170.65) with HTTP (WebMailUI); Tue, 31 Jan 2006 05:23:39 -0500 X-Mailer: Netscape WebMail 15106 Content-Type: text/plain; charset="iso-8859-1"; format=flowed MIME-Version: 1.0 To: freebsd-questions@freebsd.org X-AOL-IP: 64.12.170.65 X-Spam-Flag: NO Subject: How many IP address aliases can practically be used on one physical Ethernet interface? X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 31 Jan 2006 10:23:47 -0000 Hi, I am implementing and using a test bed simulating a huge amount of IP=20 clients, each preferable having a unique IP address. There is no, no=20 way to have an individual physical interface for each simulated client=20 so I use IP aliases. Currently it runs on Linux and there is a limit of=20 256 IP addresses per interface, among other things due to a hard array=20 limit in Linux net-tools ifconfig. There also seems to be other=20 limitations like linear searches in net-tools as well as in kernel=20 networking code. Just changing the array limit changed the problem to=20 being one of stability and performance. So I became quite optimistic reading about Virtual Hosts and IP aliases=20 in the FreeBSD handbook chapter 11.9: http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/configtuning-vi rtual-hosts.html "A given network interface has one "real" address, and may have any=20 number of "alias" addresses". So is this really true and where is the catch? Will a FreeBSD 6.0=20 accept for example 8190 IP address aliases each on say five physical=20 Ethernet interfaces? Will IP addresses be manageable to add, list and=20 delete? And how much will networking performance degrade compared to=20 using just a few aliases? I can add that there is no forwarding or routing through a simulator=20 box except IP traffic to and from the client simulation running inside. I am maybe willing to change to BSD if there is a chance of success,=20 most Guru UNIX sysadmins running real production say mostly good things=20 about the BSDs. I just need some encouragement... ;-) Best Regards Flyer ___________________________________________________ Try the New Netscape Mail Today! Virtually Spam-Free | More Storage | Import Your Contact List http://mail.netscape.com