フリー問題

問題文

The lower layer opens its sessions over the physical links while the upper layer opens its own over the device loopbacks. Which role does that difference serve?

選択肢

1. That difference provides gateway address sharing throughout the layered tenant infrastructure.
2. That difference provides keepalive segment numbering throughout the layered tenant infrastructure.
3. That difference provides designated forwarder election throughout the layered tenant infrastructure.
4. That difference provides layered session separation throughout the layered tenant infrastructure.