Rate limiting UDP,Multicast,ICMP

Brian bri at sonicboom.org
Thu Nov 15 15:07:06 UTC 2001

I have alao heard of providers who have rate limited icmp on their own
backbone links, or links facing peering partners, just something else to


----- Original Message -----
From: "David Schwartz" <davids at webmaster.com>
To: <TGainer at e-xpedient.com>; <nanog at merit.edu>
Sent: Wednesday, November 14, 2001 2:53 PM
Subject: Re: Rate limiting UDP,Multicast,ICMP

> On Tue, 13 Nov 2001 12:42:01 -0500, Thomas Gainer wrote:
> >A little more information.  We sell 100Mb Ethernet pipes to the Internet.
> >(Yes, there are a few of us left).  A fair number of these customers are
> >small businesses.  Usually, they have servers but very little IT support
> >even less IT know how.  My thought is to rate limit UDP and ICMP at the
> >customer port to no more than 3Mb/s so WHEN (not if) a customer is
> >compromised, the effects are somewhat limited and my MAN pipes have some
> >measure protection.  The question is, what am I not thinking of?  DNS,
> >and such should all operate virtually unaffected, as they are not
> >hungry services.
> Are you rate limiting only inbound? Or both ways? Are you trying to
> your customers from attack or prevent them from being the source of
> if their machines are compromised? Or both?
> If you rate-limit UDP outbound, you make it very hard for your customers
> source streaming media. If you rate-limit inbound, you make it very hard
> your customers to reflect streaming media. So long as you let your
> know what you're doing in advance, you shouldn't have any problems.
> You may wish to allow clueful customers to opt out of this filtering
> (ideally selectively) if they do wish to do things with high-bandwidth UDP
> applications. It wouldn't be unreasonable to require customers opting out
> such filtering to assume responsibility/liability for any floods that
> affect them as a result. You may wish to charge them for your costs
> with floods they originate that affect others as well.
> DS

More information about the NANOG mailing list