IP Addressing Fundamentals

RFC 2267, “Source Address Assurance”

RFC 2267, “Source Address Assurance,” was published in January 1998 with the intent of defeating certain types of DoS attacks in IP-based networks. As you learned in the preceding section, DoS attacks are insidious threats to the stability of any network or networked computer. Logically, then, anything you can do to defend against the DoS attack is a good thing. Or is it? In the case of Source Address Assurance, the cure might be worse than the disease. Curiously, many “experts” cite RFC 2267 as the best defense against a DoS attack—distributed or otherwise.

Defending Against DoS

Knowing what a DoS attack is and knowing what to do about it are two very different things. The trick is getting the spurious traffic ...