The host firewall is mainly used to protect the host from attacks and intrusions from the network.

UDP port scanning means that the attacker sends a zero-byte UDP packet to a specific port of the target host. If the port is open, it will return an ICMP port reachable data packet.

Which of the following are the versions of the SNMP protocol? (Multiple choice)

Which of the following description is wrong about the operating system?

IPSec VPN technology does not support NAT traversal when encapsulating with ESP security protocol, because ESP encrypts the packet header.