Subject: Re: broadcast ping response
To: John Nemeth <firstname.lastname@example.org>
From: Allen Briggs <email@example.com>
Date: 01/22/2005 21:50:55
On Sun, Jan 23, 2005 at 01:37:36AM +0000, Kentaro A. Kurahone wrote:
> Ask, and ye shall receive.
Heh. See below...
On Sun, Jan 23, 2005 at 01:42:04AM +0000, Herb Peyerl wrote:
> Pretty trivial with 'ipf'. No new code needed.
It might be interesting for those who aren't ipf/ipfilter savvy.
But... I'm curious where it's really useful:
Standard lab/lan setup: On a private LAN, the border shouldn't be
allowing directed broadcast traffic, so you'd be protecting
"your" link from fellows on the same LAN. Is this an issue?
Home/business on DSL/cable: If the NetBSD host is at the border,
the broadcast ping looks (to you) like a regular ping. I
don't see how this is a DoS. The "telco" should not be
passing the directed broadcast, so it should be coming
through the local network similar to above. If NetBSD
_is_ your router, it (a) presumably has a firewall to
which you can add the appropriate rules, and (b) defaults
to not forwarding directed broadcasts
(net.inet.ip.directed-broadcast defaults to 0).
NetBSD server in coloc or dmz seems to be similar to standard LAN
NetBSD host on a private LAN shouldn't be an issue.
Kurahone-san's patch seems pretty trivial, but I'm not sure how
real the need is...
Use NetBSD! http://www.netbsd.org/