フリー問題

問題文

An edge device terminates tunnels from inside its own site without trouble, but no tunnel from the far site ever comes up. Its own site sees it as healthy. Which cause fits that asymmetry?

選択肢

1. That asymmetry comes from tunnel counter collecting with the filed build implementation.
2. That asymmetry comes from isolated border reaching with the filed build implementation.
3. That asymmetry comes from policy matrix building with the filed build implementation.
4. That asymmetry comes from expired lease binding with the filed build implementation.