In IPsec, what is the role of IKE?

• A. Encrypts all data with DES
• B. Determines network routes for VPN traffic
• C. Negotiates IPsec security associations
• D. Stores user credentials for authentication

Answer: (C)

IKE is the mechanism that sets up trust and cryptographic parameters for IPsec. Its main job is to negotiate security associations between two endpoints, which define how traffic will be protected: which encryption and integrity algorithms to use, the keys, and how long those keys stay valid. It also handles mutual authentication so the peers truly are who they claim to be, all within a secure channel. Once these SAs are established, the actual data protection is performed by IPsec using the negotiated parameters, not by IKE encrypting the data itself. Routes are determined by routing protocols, not by IKE, and while credentials may be involved in the authentication step, IKE’s core purpose isn’t to store user credentials.