フリー問題

問題文

A service name can be placed in the header of an intrusion rule or given as one of the rule options. How do those two placements differ?

選択肢

1. In the header the service alone has to match, whereas as an option the rule applies to every service that the traffic could be, so the option widens it to all services at once
2. In the header the service and the ports both have to match, whereas as an option the rule applies only to the traffic that has already matched a rule with the same service in its header
3. In the header the service as well as the ports must match, whereas as an option the rule still applies when the service matches on other ports or when the ports match under another service
4. In the header the service alone has to match, whereas as an option the rule applies only when the service matches and the ports match as well, so the option is the stricter of the two placements