CORRECT TEXT
Fill in the blanks with the appropriate terms. In L2TP ______________ tunnel mode, the ISP must
support L2TP, whereas in L2TP tunnel mode, the ISP does not need to support L2TP.

Answer: compulsory

Explanation:
The Layer 2 Tunnel Protocol is one of the tunneling protocols that is used in a virtual
private network. It contains the functionality of Cisco’s Layer 2 Forwarding (L2F) protocol and
Microsoft’s Point-to-Point Tunneling Protocol (PPTP). This protocol is vendor interoperable and
supports multihopping.L2TP supports two tunnel modes:
Compulsory tunnel:
In L2TP compulsory tunnel mode, a remote host initiates a connection to its Internet Service
Provider (ISP). An L2TP connection is established between the remote user and the corporate
network by the ISP. With a compulsory tunnel, the ISP must support L2TP.
Voluntary tunnel:
In L2TP voluntary tunnel mode, the connection is created by the remote user, typically by using an
L2TP tunneling client. Then, the remote user sends L2TP packets to its ISP in order to forward
them on to the corporate network. With a voluntary tunnel, the ISP does not need to support L2TP.