Rate limiting UDP,Multicast,ICMP

Tue Nov 13 17:10:33 UTC 2001

	Some providers do rate-limit ICMP at the public exchange points.

	But they tend to only limit echo-request and echo-reply

	unreachables, p-mtu and other fun icmp messages are not
limited by these.

	I'm not aware of anyone that would limit udp traffic.  As DNS
is udp, it would not be wise to rate-limit udp flows.

	As far as multicast goes, I'm not aware of anyone running
native multicast that would limit the traffic.  Those still using
DVMRP may have multicast rate-limits in place as to not have a massive
bandwidth sucking sound coming from their general direction.

	- jared

On Tue, Nov 13, 2001 at 12:03:58PM -0500, Thomas Gainer wrote:
> 
> Is it common practice for ISPs to rate limit UDP, Multicast and ICMP on a
> customer connection to reduce the effects of various DOS attacks?  On the
> backbone?
> 
> TIA,
> 
> Thomas

-- 
Jared Mauch  | pgp key available via finger from jared at puck.nether.net
clue++;      | http://puck.nether.net/~jared/  My statements are only mine.