Huawei H12-721 Exam With Confidence Using Practice Dumps

112. The ESP only verifies the IP payload and can perform NAT traversal, but the ESP encrypts the Layer 4 port information and causes the PAT function to be unusable. This problem can be solved by using the IPSec transparent NAT function, which encapsulates the ESP packet in the UDP header and comes with the necessary port information to make the PAT work normally.

In the IPSec active/standby link backup application scenario, gateway B uses IPSec tunneling technology and gateway A to establish an IPSec VPN.

In the TCP/IP protocol, the TCP protocol provides a reliable connection service, which is implemented using a 3-way handshake. First handshake: When establishing a connection, the client sends a SYN packet (SYN=J) to the server and enters the SYN_SENT state, waiting for the server to confirm; the second handshake: the server receives the SYN packet and must send an ACK packet (ACK=1) To confirm the SYN packet of the client, and also send a SYN packet (SYN=K), that is, the SYN-ACK packet, the server enters the SYN_RCVD state; the third handshake: the client receives the SYN-ACK packet of the server. Send the acknowledgement packet ACK (SYN=2 ACK=3) to the server. After the packet is sent, the client and server enter the ESTABUSHED state and complete the handshake. Regarding the three parameters in the 3-way handshake process, which one is correct?