The Components of the ProL2TP Suite

The ProL2TP suite consists of three primary user space components:

• prol2tpd, an L2TP daemon;
• propppd, a PPP daemon;
• and proacd, an L2TP access concentrator.

These components can be used in combination to support the following use-cases:

prol2tpd: L2TP daemon

The ProL2TP suite L2TP daemon is called prol2tpd. It provides the control plane for L2TP tunnels and sessions: the data plane is handled within the kernel using configuration supplied by prol2tpd.

Upon startup, prol2tpd reads configuration from /etc/prol2tp/prol2tpd.conf, and reads the license file /etc/prol2tp/license.dat for licensing information. If the license file is not present, prol2tpd will start up in demonstration/evaluation mode which will limit its capabilities.

The daemon is controlled using a management interface application prol2tp. By default prol2tpd logs using syslog. It can be monitored using prol2tpwatch to monitor prol2tpd events, and by prol2tp to actively query system state.

For debugging, it can be convenient to run prol2tpd in the foreground, logging to stdout/stderr rather than syslog (see the prol2tpd man page for more details):

$ prol2tpd -f -d -d

prol2tpd makes use of a plugin system for supporting optional features. The plugins are loaded automatically, scanning an install directory. Some plugins are enabled by config.

prol2tpd offers a number of user script integration points. These hook scripts are called when sessions are created, destroyed, come up, or are bought down. For more information, refer to the USER_SCRIPTS section of the prol2tpd man page.

propppd: PPP daemon

The ProL2TP suite PPP daemon is called propppd. It provides the control plane for PPP sessions: the data plane is handled within the kernel using configuration supplied by propppd.

Upon startup, propppd reads configuration from /etc/proppp/propppd.conf, and reads the license file /etc/proppp/license.dat for licensing information. If the license file is not present, propppd will start up in demonstration/evaluation mode which will limit its capabilities.

The daemon is controlled using a management interface application propppctl. By default propppd logs using syslog. It can be monitored using propppwatch to monitor events.

For debugging, propppd can be run in the foreground, logging to stdout/stderr (see the propppd man page for more details):

$ propppd -f -d -d
            

proacd: Access Concentrator daemon

The ProL2TP suite PPP Access Concentrator daemon is called proacd. It provides a PPPoE server which can route PPP sessions through L2TP tunnels by interfacing with prol2tpd, or locally terminate by interfacing with propppd.

Upon startup proacd reads configuration from /etc/proac/proacd.conf, and reads the license file /etc/proac/license.dat for licensing information. If the license file is not present, proacd will start up in demonstration/evaluation mode which will limit its capabilities.

The daemon is controlled using a management interface application proac_manage. Information about current routes can be accessed using proac_info. By default proacd logs to syslog.

For debugging, proacd can be run in the foreground, logging to stdout/stderr (see the proacd man page for more details):

$ proacd -f -D -d all