An employee of a company accesses the internal web server of the company through the firewall. The web page of the website can be opened by using a browser, but the reachability of the web server is tested by using the Ping command, and it shows that it is unreachable. What are the possible reasons?

Which of the following options arePKIentity orientationCAHow to apply for a local certificate? (multiple choice)

Which of the following descriptions about the function of the iptables table is wrong?

An engineer needs to back up the firewall configuration. Now he wants to use a command to view all the current configurations of the firewall. May I ask the command he uses is ____[fill in the blank]*

At this stage, we have mastered three source NAT technologies, namely NAT No-PAT and ______ Easy IP.