From mboxrd@z Thu Jan 1 00:00:00 1970 From: "David S. Miller" Subject: Re: [PATCH} ARP auto-sizing for 2.4.24 - 2.4.26-pre3 Date: Mon, 15 Mar 2004 13:57:53 -0800 Sender: netdev-bounce@oss.sgi.com Message-ID: <20040315135753.28b945fa.davem@redhat.com> References: <20040315134412.314b5e23.davem@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: timg@tpi.com, anton@samba.org, netdev@oss.sgi.com, linux-net@vger.kernel.org Return-path: To: Pekka Savola In-Reply-To: Errors-to: netdev-bounce@oss.sgi.com List-Id: netdev.vger.kernel.org On Mon, 15 Mar 2004 23:55:04 +0200 (EET) Pekka Savola wrote: > Isn't there a problem when an outside attacker brute-force pings every > IP address in some order? The intent here is to overload the router > to do a lot of ARP/ND requests which result to nothing. Since another request for the same IP won't spam out another ARP request whilst we have an existing entry in state "resolve in progress", the damage is quite limited I'd say. Sounds to me like the backlog of packets we keep around for each "resolve in progress" neighbour cache entry is more interesting for DoS purposes :-)