From owner-freebsd-net@FreeBSD.ORG Fri May 12 02:39:33 2006 Return-Path: X-Original-To: freebsd-net@freebsd.org Delivered-To: freebsd-net@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id CD0FB16A42B for ; Fri, 12 May 2006 02:39:33 +0000 (UTC) (envelope-from rwatson@FreeBSD.org) Received: from cyrus.watson.org (cyrus.watson.org [209.31.154.42]) by mx1.FreeBSD.org (Postfix) with ESMTP id F095843EC9 for ; Fri, 12 May 2006 02:05:32 +0000 (GMT) (envelope-from rwatson@FreeBSD.org) Received: from fledge.watson.org (fledge.watson.org [209.31.154.41]) by cyrus.watson.org (Postfix) with ESMTP id 6153746D33; Thu, 11 May 2006 22:05:31 -0400 (EDT) Date: Fri, 12 May 2006 03:05:31 +0100 (BST) From: Robert Watson X-X-Sender: robert@fledge.watson.org To: Bruce M Simpson In-Reply-To: <20060509131517.GB79277@spc.org> Message-ID: <20060512030152.X20138@fledge.watson.org> References: <20060509122801.GA65297@spc.org> <20060509131517.GB79277@spc.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Cc: freebsd-net@freebsd.org, pavlin@icir.org, atanu@icir.org Subject: Re: IP_MAX_MEMBERSHIPS story. X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 12 May 2006 02:39:38 -0000 On Tue, 9 May 2006, Bruce M Simpson wrote: > On Tue, May 09, 2006 at 01:28:01PM +0100, Bruce M Simpson wrote: >> A user recently reported a problem with running into IP_MAX_MEMBERSHIPS >> on a system running FreeBSD with IPv4 forwarding enabled, and running >> the OSPF routing protocol. > > More background. People may be wondering why this is even an issue for > FreeBSD as a router. > > The answer: the imo_membership array contains members which exist as > separate entries for each ifnet in the system, and the system where this was > observed to be a problem had a number of ifnet interfaces which was larger > than IP_MAX_MEMBERSHIPS (20). I'm loosely of the opinion that the membership array should be variable length, and that we should default it to 20, but have a significantly larger maximum. It's not horribly efficient, but also wouldn't be so particularly terrible either. Robert N M Watson