xl2tpd is an implementation of the Layer 2 Tunneling Protocol (RFC 2661). L2TP allows to tunnel PPP over UDP. Some ISPs use L2TP to tunnel user sessions from dial-in servers (modem banks, ADSL DSLAMs) to back-end PPP servers. Another important application is Virtual Private Networks where the IPsec protocol is used to secure the L2TP connection (L2TP/IPsec, RFC 3193).
xl2tpd works by opening a pseudo-tty for communicating with pppd. It runs completely in userspace but supports kernel mode L2TP.
xl2tpd supports IPsec SA Reference tracking to enable overlapping internak NAT'ed IP's by different clients (eg all clients connecting from their linksys internal IP 192.168.1.101) as well as multiple clients behind the same NAT router.
xl2tpd-control [-c PATH] <COMMAND> <TUNNEL_NAME> [Options]
This option specifies xl2tpd control file.
This option enables debugging mode.
Adds new or modify existing LAC (L2TP Access Concentrator) configuration. Configuration should be specified as a command options in <key>=<value> pairs format. See available options in xl2tpd.conf(5).
Establish new connection to LAC. Username and secret for tunnel can be passed as a command options.
Removes existing LAC configuration. xl2tpd disconnects the tunnel before removing.
Adds new or modify existing LNS (L2TP Network Server) configuration.
Removes existing LNS configuration.
Check the status of LNS.
Please use the github project page https://github.com/xelerance/xl2tpd to send bugreports, issues and any other feedback.
xl2tpd.conf(5), xl2tpd(8), pppd(8)
This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with this program (see the file LICENSE); if not, see https://www.gnu.org/licenses/, or contact Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
Alexander Dorokhov <firstname.lastname@example.org>
Alexander Naumov <email@example.com>
Forked from l2tpd by Xelerance: https://github.com/xelerance/xl2tpd
Michael Richardson <firstname.lastname@example.org>
Paul Wouters <email@example.com>
Samir Hussain <firstname.lastname@example.org>
Previous development was hosted at sourceforge (http://www.sourceforge.net/projects/l2tpd) by:
Scott Balmos <email@example.com>
David Stipp <firstname.lastname@example.org>
Jeff McAdams <email@example.com>
Based off of l2tpd version 0.61. Many thanks to Jacco de Leeuw <firstname.lastname@example.org> for maintaining l2tpd.
Copyright (C)1998 Adtran, Inc.
Mark Spencer <email@example.com>