問題文
Another protection on the same port checks whether a frame is really allowed to use the source address it carries. Where does the switch get the information for that check?
選択肢
- It queries the gateway of the segment for the owner of the address, and it then forwards the frame if the gateway confirms the ownership of it.
- It compares the source of each frame against the addresses that the routing process has installed, and it then forwards the frame if a matching route exists.
- It builds a table from the address assignments that it observed passing over that port, and it then compares the source of each frame against the entry it recorded.
- It reads the list of permitted addresses from the configuration that the operator entered for that port, and it then compares the source of each frame against it.