フリー問題

問題文

A filter that steers traffic to a named instance is written on an outgoing port rather than on an incoming one. How far have the packets got by the time the filter sees them, and how does matching by the class of a source, and the tally held by class, fare once such a filter is attached to it?

選択肢

1. They have been through at least one lookup already, and once the filter has sorted them they are handed to another table to be looked up again, while the port keeps matching on the class of a source and keeps the tally kept by class of source and of destination just as before
2. They have not been looked up so far, since the filter stands in front of the lookup, and once it has sorted them they leave by the very port the filter sits on, while the port keeps matching on the class of a source and keeps the tally kept by class of source and of destination just as before
3. They have not been looked up so far, since the filter stands in front of the lookup, and once it has sorted them they leave by the very port the filter sits on, while the port gives up matching on the class of a source and gives up the tally kept by class of source and of destination
4. They have been through at least one lookup already, and once the filter has sorted them they are handed to another table to be looked up again, while the port gives up matching on the class of a source and gives up the tally kept by class of source and of destination