单项选择题 A Cisco router has been configured with the following command:IP nat pool nat-test 192.168.6.10 192.168.6.20 netmask 255.255.255.0his is an example of what type of NAT?（）

单项选择题 TestKing has 25 computers and decides to connect the network to the Internet.TestKing would like for all of the computers to have access to the Internet at the same time, but TestKing only has four usable publicly routable IP addresses.What should be configured on the router so that all computers can connect to the Internet simultaneously?（）

单项选择题 The Testking network is implementing dialup services for their remote employees.Testking uses several different Layer 3 protocols on the network. Authentication ofthe users connecting to the network is required for security. Additionally, some employees will be dialing long distance and will need callback support.Which protocol is the best choice for these remote access services?（）