L2TPV2 tunnel
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L2TPV2
TUNNEL
L2TP is the acronym of
Layer 2 Tunnel Protocol
and it is a standard of encapsulation used to
establish a tunnel between remote systems. The extremes of the tunnel are named
LNS
(L2TP
Network Server) and
LAC
(L2TP Access Concentrator). LNS is the server that receives the
connections, while LAC is the client that requires the connection. The connection occurs on UDP
protocol and once activated, the traffic can run within this connection in two directions by using PPP
protocol.
On Imola LAC is most used. The main configuration commands are the following.
set l2tp peer addr <ip-address>
is used to specify the IP address of the remote system.
set l2tp peer port <port>
is used to specify the UDP port to which the requests of connection should be sent. The default
value is 1701.
set l2tp peer secret <secret-key>
is used to specify the authentication key for activating the Tunnel.
set l2tp source <ipaddr>
is used to specify the IP address with which to send the connection requests. The default value is
the one associated to the physical output interface.
set l2tp interface <ifname>
is used to specify the physical interface on which the packets must be sent to activate the tunnel,
independently from the routes to reach the peer, use:
set l2tp peer hostname <hostname>
is used to appear to the server with the specified name.
set l2tp lac login <login-name> password <password>
is used to set user and password for PPP authentication.
set l2tp masquerade
set l2tp no-maquerade
is used to enable or disable PAT functions for outgoing packets on the tunnel.
set l2tp default-route
set l2tp no-default-route
is used to activate or deactivate a default static route on L2TP tunnel.
set l2tp idle <n>
is used to set inactivity of N seconds on PPP session.
set l2tp rx-idle <n>
is used to set MTU value on the PPP interface.
set l2tp mtu <val>
is used to configure MTU value on the tunnel.