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@puck.nether.net clue++; | http://puck.nether.net/~jared/ My statements are only mine.