3.9 Denial of Service Protection Details
IKE goes into DoS protection under the condition described in section 3.9.7.
Using the notation, as specified in [RFC2408] section 4.1.1, the generalized form of an IKE exchange using the DoS Protection extension is as shown in the following figure. For more information, see [RFC2409] section 5.
Figure 10: IKE using the DoS Protection extension
The description in this section uses the message numbers from the protocol sequence diagram.