Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965010AbWBGH5y (ORCPT ); Tue, 7 Feb 2006 02:57:54 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965011AbWBGH5x (ORCPT ); Tue, 7 Feb 2006 02:57:53 -0500 Received: from xproxy.gmail.com ([66.249.82.194]:62067 "EHLO xproxy.gmail.com") by vger.kernel.org with ESMTP id S965010AbWBGH5w convert rfc822-to-8bit (ORCPT ); Tue, 7 Feb 2006 02:57:52 -0500 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:to:subject:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=o8JC+7JVYZH/tQEzHEA6ocU+HHlY0ow8YariGavflFpv2qB7nBwL7kNkSG5VyhuP2k7voAoh9bMCFjpP5TuLySM+7m3aqxy5ZXwOs80RL6i4VcwpXhl2FmBb0kHk86HPRf2Af4uXQqJLEeVmbODxFOX12HWSYkAEpr+t9Ke4itM= Message-ID: <9fda5f510602062357n38292cebk3c5738ccdbee83@mail.gmail.com> Date: Tue, 7 Feb 2006 00:57:43 -0700 From: Pradeep Vincent To: "David S. Miller" , netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [Patch] 2.4.32 - Neighbour Cache (ARP) State machine bug Fixed In-Reply-To: <20060203.181839.104353534.davem@davemloft.net> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Content-Disposition: inline References: <9fda5f510511281257o364acb3gd634f8e412cd7301@mail.gmail.com> <9fda5f510602031806j2f9ef743t206c9ee2c3bef384@mail.gmail.com> <20060203.181839.104353534.davem@davemloft.net> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2061 Lines: 57 In 2.4.21, arp code uses gc_timer to check for stale arp cache entries. In 2.6, each entry has its own timer to check for stale arp cache. 2.4.29 to 2.4.32 kernels (atleast) use neither of these timers. This causes problems in environments where IPs or MACs are reassigned - saw this problem on load balancing router based networks that use VMACs. Tested this code on load balancing router based networks as well as peer-linux systems. Thanks, Signed off by: Pradeep Vincent diff -Naur old/net/core/neighbour.c new/net/core/neighbour.c --- old/net/core/neighbour.c Wed Nov 23 17:15:30 2005 +++ new/net/core/neighbour.c Wed Nov 23 17:26:01 2005 @@ -14,6 +14,7 @@ * Vitaly E. Lavrov releasing NULL neighbor in neigh_add. * Harald Welte Add neighbour cache statistics like rtstat * Harald Welte port neighbour cache rework from 2.6.9-rcX + * Pradeep Vincent Move neighbour cache entry to stale state */ #include @@ -705,6 +706,14 @@ neigh_release(n); continue; } + + /* Mark it stale - To be reconfirmed later when used */ + if (n->nud_state&NUD_REACHABLE && + now - n->confirmed > n->parms->reachable_time) { + n->nud_state = NUD_STALE; + neigh_suspect(n); + } + write_unlock(&n->lock); On 2/3/06, David S. Miller wrote: > From: Pradeep Vincent > Date: Fri, 3 Feb 2006 18:06:53 -0800 > > > Resending.. > > Your email client has tab and newline mangled the patch so it > cannot be applied. Please fix this up and also supply an > appropriate "Signed-off-by: " line. > > Thanks. > - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/