Which action is the first step in Site-To-Site IPSec?

Which action is the first step in Site-To-Site IPSec?

• A. The sending device encrypts the original packet and the session key
• B. The sending device encapsulates the encrypted data with new headers
• C. The sending device sends the encrypted packet to the destination device
• D. The destination device decrypts the data and the session key

Answer: (A)

In a Site-to-Site IPSec tunnel, the sending gateway first protects the data by encrypting the original packet using the negotiated session key. This session key is established beforehand through the IKE process and is used to transform the original payload into ciphertext, keeping it confidential as it travels across the network. After this encryption, the gateway wraps the encrypted payload with the IPSec header (ESP) and adds a new outer IP header to route the packet to the destination gateway. Only then is the packet sent over the network. When it arrives, the destination gateway removes the outer header and decrypts the payload with the same session key to restore the original packet.

In a Site-to-Site IPSec tunnel, the sending gateway first protects the data by encrypting the original packet using the negotiated session key. This session key is established beforehand through the IKE process and is used to transform the original payload into ciphertext, keeping it confidential as it travels across the network. After this encryption, the gateway wraps the encrypted payload with the IPSec header (ESP) and adds a new outer IP header to route the packet to the destination gateway. Only then is the packet sent over the network. When it arrives, the destination gateway removes the outer header and decrypts the payload with the same session key to restore the original packet.