Subject: Re: broadcast ping response
To: None <tech-net@netbsd.org>
From: Thor Lancelot Simon <tls@rek.tjls.com>
List: tech-net
Date: 01/22/2005 19:47:57
On Sat, Jan 22, 2005 at 04:42:29PM -0800, John Nemeth wrote:
> On Jun 14, 1:00pm, Eric Haszlakiewicz wrote:
> } On Sat, Jan 22, 2005 at 03:57:21PM -0800, John Nemeth wrote:
> } > Why is NetBSD 2.0 responding to broadcast ICMP ECHO REQUEST (ping)
> } > packets? Is there any way to stop it. Because this is a well known
> } > DOS most modern OSes don't respond, so I'm surprised that current
> } > versions of NetBSD do.
> }
> } DoS? How so? I would think that responding to a ping takes
> } considerably less resources than, say, responding to a connection attempt.
>
> It is a traffic amplification attack. Picture a network with 50+
> machines, which respond to broadcast packets. You send one ping packet
> to the broadcast address and get 50 back. A great way to flood a
> network with very little effort. Send a continuous stream of packets
It takes a heck of wimpy network to be flooded in *this* way.
I find machines that don't respond to broadcast pings mildly annoying.
Thor