# SPDX-License-Identifier: GPL-2.0-only # # Layer Two Tunneling Protocol (L2TP) # menuconfig L2TP tristate "Layer Two Tunneling Protocol (L2TP)" depends on (IPV6 || IPV6=n) depends on INET select NET_UDP_TUNNEL ---help--- Layer Two Tunneling Protocol From RFC 2661 <http://www.ietf.org/rfc/rfc2661.txt>. L2TP facilitates the tunneling of packets across an intervening network in a way that is as transparent as possible to both end-users and applications. L2TP is often used to tunnel PPP traffic over IP tunnels. One IP tunnel may carry thousands of individual PPP connections. L2TP is also used as a VPN protocol, popular with home workers to connect to their offices. L2TPv3 allows other protocols as well as PPP to be carried over L2TP tunnels. L2TPv3 is defined in RFC 3931 <http://www.ietf.org/rfc/rfc3931.txt>. The kernel component handles only L2TP data packets: a userland daemon handles L2TP the control protocol (tunnel and session setup). One such daemon is OpenL2TP (http://openl2tp.org/). If you don't need L2TP, say N. To compile all L2TP code as modules, choose M here. config L2TP_DEBUGFS tristate "L2TP debugfs support" depends on L2TP && DEBUG_FS help Support for l2tp directory in debugfs filesystem. This may be used to dump internal state of the l2tp drivers for problem analysis. If unsure, say 'Y'. To compile this driver as a module, choose M here. The module will be called l2tp_debugfs. config L2TP_V3 bool "L2TPv3 support" depends on L2TP help 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. config L2TP_IP tristate "L2TP IP encapsulation for L2TPv3" depends on L2TP_V3 help Support for L2TP-over-IP socket family. The L2TPv3 protocol defines two possible encapsulations for L2TP frames, namely UDP and plain IP (without UDP). This driver provides a new L2TPIP socket family with which userspace L2TPv3 daemons may create L2TP/IP tunnel sockets when UDP encapsulation is not required. When L2TP is carried in IP packets, it used IP protocol number 115, so this port must be enabled in firewalls. To compile this driver as a module, choose M here. The module will be called l2tp_ip. config L2TP_ETH tristate "L2TP ethernet pseudowire support for L2TPv3" depends on L2TP_V3 help Support for carrying raw ethernet frames over L2TPv3. From RFC 4719 <http://www.ietf.org/rfc/rfc4719.txt>. The Layer 2 Tunneling Protocol, Version 3 (L2TPv3) can be used as a control protocol and for data encapsulation to set up Pseudowires for transporting layer 2 Packet Data Units across an IP network [RFC3931]. This driver provides an ethernet virtual interface for each L2TP ethernet pseudowire instance. Standard Linux tools may be used to assign an IP address to the local virtual interface, or add the interface to a bridge. If you are using L2TPv3, you will almost certainly want to enable this option. To compile this driver as a module, choose M here. The module will be called l2tp_eth.