RE: Real-Time Mitigation of Denial of Service Attacks Now Available With AT&T

Jon R. Kibler wrote:
IMHO, there is absolutely no excuse for not doing ingress and
egress filtering. In fact, if you are an ISP, I would argue
that you are negligent in your fiduciary responsibilities to
your customers and shareholders if you are not filtering
source IP addresses.

Hey, I'm all for it. Where's the money and the staff?


The money is from your customers, and the staff is your staff. This scales nicely as the number of customers you have, and therefore your money and staff, is directly related to the effort you have to put into the system.

The Internet is a collective. The whole thing does not work if everyone does not help to keep the whole, well, whole.

If DDoS gets out of hand, if BGP churn is too high, if spam gets out of hand, if, if, if.

Of course, if everyone filtered ISPs who did not validate the source IPs of packets originating in their network the way some networks filter spam sources, the problem would likely correct itself quickly. The problem is figuring out which providers do not validate source addresses since, by definition, the problem we are discussing are spoofed source addresses.... =)

set routing-options forwarding-table unicast-reverse-path feasible-paths
set interfaces yy-x/x/x unit 0 family inet rpf-check

What else do you need?

Or did you buy crap that doesn't support (good) uRPF, or even doesn't
support (line-rate) filtering? Change the vendors and filter at your
core connecting those crappy boxes then.