問題文
Two ways of resolving names over an encrypted channel are compared. One is given a port of its own and the other rides inside ordinary web traffic. What does that difference mean for a firewall?
選択肢
- The one with a port of its own can be told apart and refused on the port number alone, whereas the one riding inside web traffic shares its port with the sessions a site cannot refuse
- The one with its own port shares that port with the sessions a site cannot refuse, whereas the one riding inside web traffic can be told apart and refused on the port number alone
- Neither of them can be told apart and refused on the port number alone, whereas the difference between them shows up only in which side is allowed to begin the exchange
- Both of them can be told apart and refused on the port number alone, whereas the difference between them shows up only in how many round trips each of them needs before the first answer