Question
If IPSec provides security at the network layer, why is it that security mechanisms are still needed at layers above IP?

Answer

IPSec protects traffic across the Internet but once you’re connected to the corporate network, that traffic is in the clear. IPsec supports network-level peer authentication, data origin authentication, data purity, and data encryption.
Therefore security mechanisms are still needed at layers above IP using IPsec as it help us get protected from :
1.Network-based attacks from untrusted computers.
2.Attacks that can result in the denial-of-service of applications.
3.Data corruption
4.Data theft
5.User-credential theft
6.Administrative control of network, computers, and server.

Place your order now to access full answer