A.True

B.False

A.False

B.True

A.Symmetric encryption algorithm

B.Asymmetric encryption algorithm

A.General network security incidents

B.Major network security incidents

C.Special network security incidents

A.NAT technology can effectively hide the costs of the LAN; it is an effective network security protection technology

B.Address Translation can follow the needs of users, providing FTP, WWW, Telnet and other services outside the LAN

C.Some application layer protocols carry IP address information in the data, but also modify the IP address information in the data of the upper layer when they are as NAT

D.For some non-TCP, UDP protocols (such as ICMP, PPTP), unable to do the NAT translation