From owner-freebsd-isp Fri Apr 7 5: 7:15 2000 Delivered-To: freebsd-isp@freebsd.org Received: from internal.mail.demon.net (internal.mail.demon.net [193.195.224.3]) by hub.freebsd.org (Postfix) with ESMTP id 308B737B8D2 for ; Fri, 7 Apr 2000 05:07:09 -0700 (PDT) (envelope-from fanf@demon.net) Received: from fanf.eng.demon.net (fanf.eng.demon.net [195.11.55.89]) by internal.mail.demon.net with ESMTP id NAA01208; Fri, 7 Apr 2000 13:06:56 +0100 (BST) Received: from fanf by fanf.eng.demon.net with local (Exim 3.12 #3) id 12dXXD-0005UH-00; Fri, 07 Apr 2000 13:06:47 +0100 To: jgreco@ns.sol.net From: Tony Finch Cc: isp@freebsd.org Subject: Re: flat network In-Reply-To: <200004090128.UAA92724@aurora.sol.net> References: <38ECE636.CE86D01C@nyi.net> Message-Id: Date: Fri, 07 Apr 2000 13:06:47 +0100 Sender: owner-freebsd-isp@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org Joe Greco wrote: > >If you have one router and one machine on a network, with ARP you still have >the potential to have as many ARP entries as you do virtual servers. If you >would like a practical demonstration of why this is bad, go generate about >65,000 virtual servers on such a machine, and then ask for stuff from all of >them. Note the behaviour of the ARP cache on your routers and switches. >The behaviour is O(N), and you are screwed when N exceeds the capacity of >the ARP table on the device. God forbid you've more than one server on the >net! We put all our IP aliases on the loopback interface to avoid the ARP problem. The patch in PR#12071 is handy too. Tony. -- f.a.n.finch fanf@demon.net dot@dotat.at 397 tundra clump under-scrub To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-isp" in the body of the message