H12-721 Question #100: Real Exam Question with Answer & Explanation

IPSec NAT traversal is not supported in IKE main mode and aggressive mode of IP addresses + pre-shared key authentication mode, because the pre-shared key authentication requires the extraction of IP packets in order to find the IP address of the source address of the corresponding pre-shared secret key, and the presence of NAT causes a change to make the device unable to find the address of a pre-shared key.