L2TPv3 support

configname: CONFIG_L2TP_V3

Linux Kernel Configuration
└─>Networking support
└─>Networking options
└─>Layer Two Tunneling Protocol (L2TP)
└─>L2TPv3 support
In linux kernel since version 2.6.35 (release Date: 2010-08-01)  
Layer Two Tunneling Protocol Version 3

From RFC 3931 <http://www.ietf.org/rfc/rfc3931.txt>.

The Layer Two Tunneling Protocol (L2TP) provides a dynamic
mechanism for tunneling Layer 2 (L2) "circuits" across a
packet-oriented data network (e.g., over IP). L2TP, as
originally defined in RFC 2661, is a standard method for
tunneling Point-to-Point Protocol (PPP) [RFC1661] sessions.
L2TP has since been adopted for tunneling a number of other
L2 protocols, including ATM, Frame Relay, HDLC and even raw
ethernet frames.

If you are connecting to L2TPv3 equipment, or you want to
tunnel raw ethernet frames using L2TP, say Y here. If
unsure, say N.