Huawei Certified Network Professional HCNP H12-721 Reddit Questions

In dual-system hot backup, the backup channel must be the primary interface on the interface board. Which type is not supported?

The ip-link principle is to continuously send ICMP packets or ARP request packets to the specified destination address, and check whether the ICMP echo reply or ARP reply packet of the destination IP response can be received.

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?

When an IPSec VPN is set up on both ends of the firewall, the security ACL rules of both ends are mirrored.