From owner-freebsd-bugs@FreeBSD.ORG Mon May 26 01:00:08 2008 Return-Path: Delivered-To: freebsd-bugs@hub.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id E23AF106567B for ; Mon, 26 May 2008 01:00:08 +0000 (UTC) (envelope-from gnats@FreeBSD.org) Received: from freefall.freebsd.org (freefall.freebsd.org [IPv6:2001:4f8:fff6::28]) by mx1.freebsd.org (Postfix) with ESMTP id AA0588FC14 for ; Mon, 26 May 2008 01:00:08 +0000 (UTC) (envelope-from gnats@FreeBSD.org) Received: from freefall.freebsd.org (gnats@localhost [127.0.0.1]) by freefall.freebsd.org (8.14.2/8.14.2) with ESMTP id m4Q108oW090277 for ; Mon, 26 May 2008 01:00:08 GMT (envelope-from gnats@freefall.freebsd.org) Received: (from gnats@localhost) by freefall.freebsd.org (8.14.2/8.14.1/Submit) id m4Q108Hu090276; Mon, 26 May 2008 01:00:08 GMT (envelope-from gnats) Resent-Date: Mon, 26 May 2008 01:00:08 GMT Resent-Message-Id: <200805260100.m4Q108Hu090276@freefall.freebsd.org> Resent-From: FreeBSD-gnats-submit@FreeBSD.org (GNATS Filer) Resent-To: freebsd-bugs@FreeBSD.org Resent-Reply-To: FreeBSD-gnats-submit@FreeBSD.org, Barrett Lyon Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 03967106566C for ; Mon, 26 May 2008 00:52:34 +0000 (UTC) (envelope-from nobody@FreeBSD.org) Received: from www.freebsd.org (www.freebsd.org [IPv6:2001:4f8:fff6::21]) by mx1.freebsd.org (Postfix) with ESMTP id D92D58FC0C for ; Mon, 26 May 2008 00:52:33 +0000 (UTC) (envelope-from nobody@FreeBSD.org) Received: from www.freebsd.org (localhost [127.0.0.1]) by www.freebsd.org (8.14.2/8.14.2) with ESMTP id m4Q0p0bh095868 for ; Mon, 26 May 2008 00:51:00 GMT (envelope-from nobody@www.freebsd.org) Received: (from nobody@localhost) by www.freebsd.org (8.14.2/8.14.1/Submit) id m4Q0p0IY095865; Mon, 26 May 2008 00:51:00 GMT (envelope-from nobody) Message-Id: <200805260051.m4Q0p0IY095865@www.freebsd.org> Date: Mon, 26 May 2008 00:51:00 GMT From: Barrett Lyon To: freebsd-gnats-submit@FreeBSD.org X-Send-Pr-Version: www-3.1 Cc: Subject: kern/123991: ECMP balancing issues X-BeenThere: freebsd-bugs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 26 May 2008 01:00:09 -0000 >Number: 123991 >Category: kern >Synopsis: ECMP balancing issues >Confidential: no >Severity: non-critical >Priority: low >Responsible: freebsd-bugs >State: open >Quarter: >Keywords: >Date-Required: >Class: sw-bug >Submitter-Id: current-users >Arrival-Date: Mon May 26 01:00:08 UTC 2008 >Closed-Date: >Last-Modified: >Originator: Barrett Lyon >Release: 8.0-CURRENT >Organization: >Environment: FreeBSD home.blyon.com 8.0-CURRENT FreeBSD 8.0-CURRENT #3: Sun May 25 02:18:13 PDT 2008 blyon@home.blyon.com:/usr/obj/usr/src/sys/GENERIC i386 CVSUP as of May 25th >Description: Using RADIX_MPATH support in the kernel provides the desired ECMP support, however ECMP does not appear to load balance properly. The first route appears to be a primary route, were the second path becomes almost a backup route. Removing the first and re-adding it causes the preference to swap. This is also seen in the netstat -rn "Use" output, where the counter on the => route is always higher than the secondary route. The destination IPs are very mixed. The desired effect would be a better load distribution across the two next-hops or even per-packet load balancing as an option. >How-To-Repeat: Add two routes with different next-hops, the first route becomes the preference route. >Fix: none >Release-Note: >Audit-Trail: >Unformatted: