問題文
A speaker wants to undo the tie it once announced between a label and a prefix. Which ties can that method not reach, and what else does its message remove?
選択肢
- A tie never announced on the session at hand is out of reach, unless it was announced to the same peer on an earlier session that this one restarted gracefully from, and the message leaves the path to that prefix standing just as it was, so a separate withdrawal has to be sent for it before the path will go away
- Every tie is within reach whatever session announced it, the encoding naming the prefix rather than the session, and the message also takes back the path to that prefix that the session had announced before
- Every tie is within reach whatever session announced it, the encoding naming the prefix rather than the session, and the message leaves the path to that prefix standing just as it was, so a separate withdrawal has to be sent for it before the path will go away
- A tie never announced on the session at hand is out of reach, unless it was announced to the same peer on an earlier session that this one restarted gracefully from, and the message also takes back the path to that prefix that the session had announced before