I'd like to hear more about the filtering capabilities of the cable modems. Is there somewhere I could find the provider-oriented documentation (as opposed to the two-pager given to consumers with the modems)? I'd like to see if additional uses of this filtering could be made which would increase the user's security (e.g. filtering out ports 137-139 TCP and UDP to prevent neighbors from attacking neighbors), and that of the Internet (ingress filtering). I believe you're correct that sufficient tools exist today to protect DHCP in cable modem and switched Ethernet environments. I don't believe there's sufficient knowledge of that information spread around. As such, I was thinking of writing an informational RFC on the subject, and would be interested in having your input, especially from the cable modem plant angle. Interested? Dan -- ----------------------------------------------------------------- Daniel Senie dts@senie.com Amaranth Networks Inc. http://www.amaranthnetworks.com