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Rewritten the L2TP documentation

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Rewritten the L2TP documentation
Added the example 'PPPoE over L2TP' to blueprints
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aapostoliuk 2024-02-21 16:57:34 +02:00
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@ -17,6 +17,7 @@ This chapter contains various configuration examples:
wan-load-balancing
pppoe-ipv6-basic
l3vpn-hub-and-spoke
lac-lns
inter-vrf-routing-vrf-lite
qos
segment-routing-isis

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:lastproofread: 2024-02-21
.. _examples-lac-lns:
###############
PPPoE over L2TP
###############
This document is to describe a basic setup using PPPoE over L2TP.
LAC and LNS are components of the broadband topology.
LAC - L2TP access concentrator
LNS - L2TP Network Server
LAC and LNS forms L2TP tunnel. LAC receives packets from PPPoE clients and
forward them to LNS. LNS is the termination point that comes from PPP packets
from the remote client.
In this example we use VyOS 1.5 as LNS and Cisco IOS as LAC.
All users with domain **vyos.io** will be tunneled to LNS via L2TP.
Network Topology
================
.. image:: /_static/images/lac-lns-diagram.jpg
:width: 60%
:align: center
:alt: Network Topology Diagram
Configurations
==============
LAC
---
.. code-block:: none
aaa new-model
!
aaa authentication ppp default local
!
vpdn enable
vpdn aaa attribute nas-ip-address vpdn-nas
!
vpdn-group LAC
request-dialin
protocol l2tp
domain vyos.io
initiate-to ip 192.168.139.100
source-ip 192.168.139.101
local name LAC
l2tp tunnel password 0 test123
!
bba-group pppoe MAIN-BBA
virtual-template 1
!
interface GigabitEthernet0/0
description To LNS
ip address 192.168.139.101 255.255.255.0
duplex auto
speed auto
media-type rj45
!
interface GigabitEthernet0/1
description To PPPoE clients
no ip address
duplex auto
speed auto
media-type rj45
pppoe enable group MAIN-BBA
!
LNS
---
.. code-block:: none
set interfaces ethernet eth0 address '192.168.139.100/24'
set nat source rule 100 outbound-interface name 'eth0'
set nat source rule 100 source address '10.0.0.0/24'
set nat source rule 100 translation address 'masquerade'
set protocols static route 0.0.0.0/0 next-hop 192.168.139.2
set vpn l2tp remote-access authentication mode 'radius'
set vpn l2tp remote-access authentication radius server 192.168.139.110 key 'radiustest'
set vpn l2tp remote-access client-ip-pool TEST-POOL range '10.0.0.2-10.0.0.100'
set vpn l2tp remote-access default-pool 'TEST-POOL'
set vpn l2tp remote-access gateway-address '10.0.0.1'
set vpn l2tp remote-access lns host-name 'LAC'
set vpn l2tp remote-access lns shared-secret 'test123'
set vpn l2tp remote-access name-server '8.8.8.8'
set vpn l2tp remote-access ppp-options disable-ccp
.. note:: This setup requires the Compression Control Protocol (CCP)
being disabled, the command ``set vpn l2tp remote-access ppp-options disable-ccp``
accomplishes that.
Client
------
In this lab we use Windows PPPoE client.
.. image:: /_static/images/lac-lns-winclient.jpg
:width: 100%
:align: center
:alt: Window PPPoE Client Configuration
Monitoring
----------
Monitoring on LNS side
.. code-block:: none
vyos@vyos:~$ show l2tp-server sessions
ifname | username | ip | ip6 | ip6-dp | calling-sid | rate-limit | state | uptime | rx-bytes | tx-bytes
--------+--------------+----------+-----+--------+-----------------+------------+--------+----------+-----------+----------
l2tp0 | test@vyos.io | 10.0.0.2 | | | 192.168.139.101 | | active | 00:00:35 | 188.4 KiB | 9.3 MiB
Monitoring on LAC side
.. code-block:: none
Router#show pppoe session
1 session in FORWARDED (FWDED) State
1 session total
Uniq ID PPPoE RemMAC Port VT VA State
SID LocMAC VA-st Type
1 1 000c.290b.20a6 Gi0/1 1 N/A FWDED
0c58.88ac.0001
Router#show l2tp
L2TP Tunnel and Session Information Total tunnels 1 sessions 1
LocTunID RemTunID Remote Name State Remote Address Sessn L2TP Class/
Count VPDN Group
23238 2640 LAC est 192.168.139.100 1 LAC
LocID RemID TunID Username, Intf/ State Last Chg Uniq ID
Vcid, Circuit
25641 25822 23238 test@vyos.io, Gi0/1 est 00:05:36 1
Monitoring on RADIUS Server side
.. code-block:: none
root@Radius:~# cat /var/log/freeradius/radacct/192.168.139.100/detail-20240221
Wed Feb 21 13:37:17 2024
User-Name = "test@vyos.io"
NAS-Port = 0
NAS-Port-Id = "l2tp0"
NAS-Port-Type = Virtual
Service-Type = Framed-User
Framed-Protocol = PPP
Calling-Station-Id = "192.168.139.101"
Called-Station-Id = "192.168.139.100"
Acct-Status-Type = Start
Acct-Authentic = RADIUS
Acct-Session-Id = "45c731e169d9a4f1"
Acct-Session-Time = 0
Acct-Input-Octets = 0
Acct-Output-Octets = 0
Acct-Input-Packets = 0
Acct-Output-Packets = 0
Acct-Input-Gigawords = 0
Acct-Output-Gigawords = 0
Framed-IP-Address = 10.0.0.2
NAS-IP-Address = 192.168.139.100
Event-Timestamp = "Feb 21 2024 13:37:17 UTC"
Tmp-String-9 = "ai:"
Acct-Unique-Session-Id = "ea6a1089816f19c0d0f1819bc61c3318"
Timestamp = 1708522637

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@ -1,30 +1,80 @@
.. _l2tp:
####
L2TP
----
####
VyOS utilizes accel-ppp_ to provide L2TP server functionality. It can be used
with local authentication or a connected RADIUS server.
L2TP over IPsec
===============
***********************
Configuring L2TP Server
***********************
Example for configuring a simple L2TP over IPsec VPN for remote access (works
with native Windows and Mac VPN clients):
.. code-block:: none
set vpn l2tp remote-access authentication mode local
set vpn l2tp remote-access authentication local-users username test password 'test'
set vpn l2tp remote-access client-ip-pool L2TP-POOL range 192.168.255.2-192.168.255.254
set vpn l2tp remote-access default-pool 'L2TP-POOL'
set vpn l2tp remote-access outside-address 192.0.2.2
set vpn l2tp remote-access gateway-address 192.168.255.1
.. cfgcmd:: set vpn l2tp remote-access authentication mode <local | radius>
Set authentication backend. The configured authentication backend is used
for all queries.
* **radius**: All authentication queries are handled by a configured RADIUS
server.
* **local**: All authentication queries are handled locally.
.. cfgcmd:: set vpn l2tp remote-access authentication local-users username <user> password
<pass>
Create `<user>` for local authentication on this system. The users password
will be set to `<pass>`.
.. cfgcmd:: set vpn l2tp remote-access client-ip-pool <POOL-NAME> range <x.x.x.x-x.x.x.x | x.x.x.x/x>
Use this command to define the first IP address of a pool of
addresses to be given to l2tp clients. If notation ``x.x.x.x-x.x.x.x``,
it must be within a /24 subnet. If notation ``x.x.x.x/x`` is
used there is possibility to set host/netmask.
.. cfgcmd:: set vpn l2tp remote-access default-pool <POOL-NAME>
Use this command to define default address pool name.
.. cfgcmd:: set vpn l2tp remote-access gateway-address <gateway>
Specifies single `<gateway>` IP address to be used as local address of PPP
interfaces.
*****************
Configuring IPsec
*****************
.. code-block:: none
set vpn ipsec interface eth0
set vpn l2tp remote-access outside-address 192.0.2.2
set vpn l2tp remote-access client-ip-pool L2TP-POOL range 192.168.255.2-192.168.255.254
set vpn l2tp remote-access default-pool 'L2TP-POOL'
set vpn l2tp remote-access ipsec-settings authentication mode pre-shared-secret
set vpn l2tp remote-access ipsec-settings authentication pre-shared-secret <secret>
set vpn l2tp remote-access authentication mode local
set vpn l2tp remote-access authentication local-users username test password 'test'
In the above example, an external IP of 192.0.2.2 is assumed.
.. cfgcmd:: set vpn ipsec interface <INTERFACE>
Use this command to define IPsec interface.
.. cfgcmd:: set vpn l2tp remote-access ipsec-settings authentication mode <pre-shared-secret | x509>
Set mode for IPsec authentication between VyOS and L2TP clients.
.. cfgcmd:: set vpn l2tp remote-access ipsec-settings authentication mode <pre-shared-secret | x509>
Set predefined shared secret phrase.
If a local firewall policy is in place on your external interface you will need
to allow the ports below:
@ -64,79 +114,9 @@ To allow VPN-clients access via your external address, a NAT rule is required:
set nat source rule 110 source address '192.168.255.0/24'
set nat source rule 110 translation address masquerade
VPN-clients will request configuration parameters, optionally you can DNS
parameter to the client.
.. code-block:: none
set vpn l2tp remote-access name-server '198.51.100.8'
set vpn l2tp remote-access name-server '198.51.100.4'
Established sessions can be viewed using the **show l2tp-server sessions**
operational command
.. code-block:: none
vyos@vyos:~$ show l2tp-server sessions
ifname | username | ip | ip6 | ip6-dp | calling-sid | rate-limit | state | uptime | rx-bytes | tx-bytes
--------+----------+---------------+-----+--------+-------------+------------+--------+----------+----------+----------
l2tp0 | test | 192.168.255.3 | | | 192.168.0.36 | | active | 02:01:47 | 7.7 KiB | 1.2 KiB
LNS (L2TP Network Server)
=========================
LNS are often used to connect to a LAC (L2TP Access Concentrator).
Below is an example to configure a LNS:
.. code-block:: none
set vpn l2tp remote-access outside-address 192.0.2.2
set vpn l2tp remote-access client-ip-pool L2TP-POOL range 192.168.255.2-192.168.255.254
set vpn l2tp remote-access default-pool 'L2TP-POOL'
set vpn l2tp remote-access lns shared-secret 'secret'
set vpn l2tp remote-access ppp-options disable-ccp
set vpn l2tp remote-access authentication mode local
set vpn l2tp remote-access authentication local-users username test password 'test'
The example above uses 192.0.2.2 as external IP address. A LAC normally requires
an authentication password, which is set in the example configuration to
``lns shared-secret 'secret'``. This setup requires the Compression Control
Protocol (CCP) being disabled, the command ``set vpn l2tp remote-access
ccp-disable`` accomplishes that.
Bandwidth Shaping
=================
Bandwidth rate limits can be set for local users or via RADIUS based attributes.
Bandwidth Shaping for local users
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
The rate-limit is set in kbit/sec.
.. code-block:: none
set vpn l2tp remote-access outside-address 192.0.2.2
set vpn l2tp remote-access client-ip-pool L2TP-POOL range 192.168.255.2-192.168.255.254
set vpn l2tp remote-access default-pool 'L2TP-POOL'
set vpn l2tp remote-access authentication mode local
set vpn l2tp remote-access authentication local-users username test password test
set vpn l2tp remote-access authentication local-users username test rate-limit download 20480
set vpn l2tp remote-access authentication local-users username test rate-limit upload 10240
vyos@vyos:~$ show l2tp-server sessions
ifname | username | ip | ip6 | ip6-dp | calling-sid | rate-limit | state | uptime | rx-bytes | tx-bytes
--------+----------+---------------+-----+--------+-------------+------------+--------+----------+----------+----------
l2tp0 | test | 192.168.255.3 | | | 192.168.0.36 | | active | 02:01:47 | 7.7 KiB | 1.2 KiB
RADIUS authentication
======================
*********************************
Configuring RADIUS authentication
*********************************
To enable RADIUS based authentication, the authentication mode needs to be
changed within the configuration. Previous settings like the local users, still
@ -146,10 +126,16 @@ accounts again.
.. code-block:: none
set vpn l2tp remote-access authentication mode <local|radius>
set vpn l2tp remote-access authentication mode radius
.. cfgcmd:: set vpn l2tp remote-access authentication radius server <server> key <secret>
Configure RADIUS `<server>` and its required shared `<secret>` for
communicating with the RADIUS server.
Since the RADIUS server would be a single point of failure, multiple RADIUS
servers can be setup and will be used subsequentially.
For example:
.. code-block:: none
@ -160,60 +146,118 @@ servers can be setup and will be used subsequentially.
queries, make sure to add your VyOS router to the allowed client list.
RADIUS source address
^^^^^^^^^^^^^^^^^^^^^
=====================
If you are using OSPF as IGP, always the closest interface connected to the
RADIUS server is used. With VyOS 1.2 you can bind all outgoing RADIUS requests
to a single source IP e.g. the loopback interface.
.. code-block:: none
.. cfgcmd:: set vpn l2tp remote-access authentication radius source-address <address>
set vpn l2tp remote-access authentication radius source-address 10.0.0.3
Above command will use `10.0.0.3` as source IPv4 address for all RADIUS queries
on this NAS.
Source IPv4 address used in all RADIUS server queires.
.. note:: The ``source-address`` must be configured on one of VyOS interface.
Best practice would be a loopback or dummy interface.
RADIUS bandwidth shaping attribute
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
RADIUS advanced options
=======================
To enable bandwidth shaping via RADIUS, the option rate-limit needs to be
enabled.
.. cfgcmd:: set vpn l2tp remote-access authentication radius server <server> port <port>
.. code-block:: none
Configure RADIUS `<server>` and its required port for authentication requests.
set vpn l2tp remote-access authentication radius rate-limit enable
.. cfgcmd:: set vpn l2tp remote-access authentication radius server <server> fail-time <time>
The default RADIUS attribute for rate limiting is ``Filter-Id``, but you may
also redefine it.
Mark RADIUS server as offline for this given `<time>` in seconds.
.. code-block:: none
.. cfgcmd:: set vpn l2tp remote-access authentication radius server <server> disable
set vpn l2tp remote-access authentication radius rate-limit attribute Download-Speed
Temporary disable this RADIUS server.
.. cfgcmd:: set vpn l2tp remote-access authentication radius acct-timeout <timeout>
Timeout to wait reply for Interim-Update packets. (default 3 seconds)
.. cfgcmd:: set vpn l2tp remote-access authentication radius dynamic-author server <address>
Specifies IP address for Dynamic Authorization Extension server (DM/CoA)
.. cfgcmd:: set vpn l2tp remote-access authentication radius dynamic-author port <port>
Port for Dynamic Authorization Extension server (DM/CoA)
.. cfgcmd:: set vpn l2tp remote-access authentication radius dynamic-author key <secret>
Secret for Dynamic Authorization Extension server (DM/CoA)
.. cfgcmd:: set vpn l2tp remote-access authentication radius max-try <number>
Maximum number of tries to send Access-Request/Accounting-Request queries
.. cfgcmd:: set vpn l2tp remote-access authentication radius timeout <timeout>
Timeout to wait response from server (seconds)
.. cfgcmd:: set vpn l2tp remote-access authentication radius nas-identifier <identifier>
Value to send to RADIUS server in NAS-Identifier attribute and to be matched
in DM/CoA requests.
.. cfgcmd:: set vpn l2tp remote-access authentication radius nas-ip-address <address>
Value to send to RADIUS server in NAS-IP-Address attribute and to be matched
in DM/CoA requests. Also DM/CoA server will bind to that address.
.. cfgcmd:: set vpn l2tp remote-access authentication radius source-address <address>
Source IPv4 address used in all RADIUS server queires.
.. cfgcmd:: set vpn l2tp remote-access authentication radius rate-limit attribute <attribute>
Specifies which RADIUS server attribute contains the rate limit information.
The default attribute is `Filter-Id`.
.. note:: If you set a custom RADIUS attribute you must define it on both
dictionaries at RADIUS server and client, which is the vyos router in our
example.
dictionaries at RADIUS server and client.
The RADIUS dictionaries in VyOS are located at ``/usr/share/accel-ppp/radius/``
.. cfgcmd:: set vpn l2tp remote-access authentication radius rate-limit enable
RADIUS advanced features
^^^^^^^^^^^^^^^^^^^^^^^^
Enables bandwidth shaping via RADIUS.
.. cfgcmd:: set vpn l2tp remote-access authentication radius rate-limit vendor
Specifies the vendor dictionary, dictionary needs to be in
/usr/share/accel-ppp/radius.
Received RADIUS attributes have a higher priority than parameters defined within
the CLI configuration, refer to the explanation below.
Allocation clients ip addresses by RADIUS
*****************************************
=========================================
If the RADIUS server sends the attribute ``Framed-IP-Address`` then this IP
address will be allocated to the client and the option ip-pool within the CLI
address will be allocated to the client and the option ``default-pool`` within the CLI
config is being ignored.
If the RADIUS server sends the attribute ``Framed-Pool``, IP address will be allocated
from a predefined IP pool whose name equals the attribute value.
If the RADIUS server sends the attribute ``Stateful-IPv6-Address-Pool``, IPv6 address
will be allocated from a predefined IPv6 pool ``prefix`` whose name equals the attribute value.
If the RADIUS server sends the attribute ``Delegated-IPv6-Prefix-Pool``, IPv6
delegation pefix will be allocated from a predefined IPv6 pool ``delegate``
whose name equals the attribute value.
.. note:: ``Stateful-IPv6-Address-Pool`` and ``Delegated-IPv6-Prefix-Pool`` are defined in
RFC6911. If they are not defined in your RADIUS server, add new dictionary_.
User interface can be put to VRF context via RADIUS Access-Accept packet, or change
it via RADIUS CoA. ``Accel-VRF-Name`` is used from these purposes. It is custom `ACCEL-PPP attribute`_.
Define it in your RADIUS server.
Renaming clients interfaces by RADIUS
*************************************
=====================================
If the RADIUS server uses the attribute ``NAS-Port-Id``, ppp tunnels will be
renamed.
@ -221,6 +265,301 @@ renamed.
.. note:: The value of the attribute ``NAS-Port-Id`` must be less than 16
characters, otherwise the interface won't be renamed.
*************************************
Configuring LNS (L2TP Network Server)
*************************************
LNS are often used to connect to a LAC (L2TP Access Concentrator).
.. cfgcmd:: set vpn l2tp remote-access lns host-name <hostname>
Sent to the client (LAC) in the Host-Name attribute
.. cfgcmd:: set vpn l2tp remote-access lns shared-secret <secret>
Tunnel password used to authenticate the client (LAC)
To explain the usage of LNS follow our blueprint :ref:`examples-lac-lns`.
****
IPv6
****
.. cfgcmd:: set vpn l2tp remote-access ppp-options ipv6 <require | prefer | allow | deny>
Specifies IPv6 negotiation preference.
* **require** - Require IPv6 negotiation
* **prefer** - Ask client for IPv6 negotiation, do not fail if it rejects
* **allow** - Negotiate IPv6 only if client requests
* **deny** - Do not negotiate IPv6 (default value)
.. cfgcmd:: set vpn l2tp remote-access client-ipv6-pool <IPv6-POOL-NAME> prefix <address>
mask <number-of-bits>
Use this comand to set the IPv6 address pool from which an l2tp client
will get an IPv6 prefix of your defined length (mask) to terminate the
l2tp endpoint at their side. The mask length can be set from 48 to 128
bit long, the default value is 64.
.. cfgcmd:: set vpn l2tp remote-access client-ipv6-pool <IPv6-POOL-NAME> delegate <address>
delegation-prefix <number-of-bits>
Use this command to configure DHCPv6 Prefix Delegation (RFC3633) on
l2tp. You will have to set your IPv6 pool and the length of the
delegation prefix. From the defined IPv6 pool you will be handing out
networks of the defined length (delegation-prefix). The length of the
delegation prefix can be set from 32 to 64 bit long.
.. cfgcmd:: set vpn l2tp remote-access default-ipv6-pool <IPv6-POOL-NAME>
Use this command to define default IPv6 address pool name.
.. code-block:: none
set vpn l2tp remote-access ppp-options ipv6 allow
set vpn l2tp remote-access client-ipv6-pool IPv6-POOL delegate '2001:db8:8003::/48' delegation-prefix '56'
set vpn l2tp remote-access client-ipv6-pool IPV6-POOL prefix '2001:db8:8002::/48' mask '64'
set vpn l2tp remote-access default-ipv6-pool IPv6-POOL
IPv6 Advanced Options
=====================
.. cfgcmd:: set vpn l2tp remote-access ppp-options ipv6-accept-peer-interface-id
Accept peer interface identifier. By default is not defined.
.. cfgcmd:: set vpn l2tp remote-access ppp-options ipv6-interface-id <random | x:x:x:x>
Specifies fixed or random interface identifier for IPv6.
By default is fixed.
* **random** - Random interface identifier for IPv6
* **x:x:x:x** - Specify interface identifier for IPv6
.. cfgcmd:: set vpn l2tp remote-access ppp-options ipv6-interface-id <random | x:x:x:x>
Specifies peer interface identifier for IPv6. By default is fixed.
* **random** - Random interface identifier for IPv6
* **x:x:x:x** - Specify interface identifier for IPv6
* **ipv4-addr** - Calculate interface identifier from IPv4 address.
* **calling-sid** - Calculate interface identifier from calling-station-id.
*********
Scripting
*********
.. cfgcmd:: set vpn l2tp remote-access extended-scripts on-change <path_to_script>
Script to run when session interface changed by RADIUS CoA handling
.. cfgcmd:: set vpn l2tp remote-access extended-scripts on-down <path_to_script>
Script to run when session interface going to terminate
.. cfgcmd:: set vpn l2tp remote-access extended-scripts on-pre-up <path_to_script>
Script to run before session interface comes up
.. cfgcmd:: set vpn l2tp remote-access extended-scripts on-up <path_to_script>
Script to run when session interface is completely configured and started
****************
Advanced Options
****************
Authentication Advanced Options
===============================
.. cfgcmd:: set vpn l2tp remote-access authentication local-users username <user> disable
Disable `<user>` account.
.. cfgcmd:: set vpn l2tp remote-access authentication local-users username <user> static-ip
<address>
Assign static IP address to `<user>` account.
.. cfgcmd:: set vpn l2tp remote-access authentication local-users username <user> rate-limit
download <bandwidth>
Download bandwidth limit in kbit/s for `<user>`.
.. cfgcmd:: set vpn l2tp remote-access authentication local-users username <user> rate-limit
upload <bandwidth>
Upload bandwidth limit in kbit/s for `<user>`.
.. cfgcmd:: set vpn l2tp remote-access authentication protocols
<pap | chap | mschap | mschap-v2>
Require the peer to authenticate itself using one of the following protocols:
pap, chap, mschap, mschap-v2.
Client IP Pool Advanced Options
===============================
.. cfgcmd:: set vpn l2tp remote-access client-ip-pool <POOL-NAME> next-pool <NEXT-POOL-NAME>
Use this command to define the next address pool name.
PPP Advanced Options
====================
.. cfgcmd:: set vpn l2tp remote-access ppp-options disable-ccp
Disable Compression Control Protocol (CCP).
CCP is enabled by default.
.. cfgcmd:: set vpn l2tp remote-access ppp-options interface-cache <number>
Specifies number of interfaces to keep in cache. It means that don’t
destroy interface after corresponding session is destroyed, instead
place it to cache and use it later for new sessions repeatedly.
This should reduce kernel-level interface creation/deletion rate lack.
Default value is **0**.
.. cfgcmd:: set vpn l2tp remote-access ppp-options ipv4 <require | prefer | allow | deny>
Specifies IPv4 negotiation preference.
* **require** - Require IPv4 negotiation
* **prefer** - Ask client for IPv4 negotiation, do not fail if it rejects
* **allow** - Negotiate IPv4 only if client requests (Default value)
* **deny** - Do not negotiate IPv4
.. cfgcmd:: set vpn l2tp remote-access ppp-options lcp-echo-failure <number>
Defines the maximum `<number>` of unanswered echo requests. Upon reaching the
value `<number>`, the session will be reset. Default value is **3**.
.. cfgcmd:: set vpn l2tp remote-access ppp-options lcp-echo-interval <interval>
If this option is specified and is greater than 0, then the PPP module will
send LCP pings of the echo request every `<interval>` seconds.
Default value is **30**.
.. cfgcmd:: set vpn l2tp remote-access ppp-options lcp-echo-timeout
Specifies timeout in seconds to wait for any peer activity. If this option
specified it turns on adaptive lcp echo functionality and "lcp-echo-failure"
is not used. Default value is **0**.
.. cfgcmd:: set vpn l2tp remote-access ppp-options min-mtu <number>
Defines minimum acceptable MTU. If client will try to negotiate less then
specified MTU then it will be NAKed or disconnected if rejects greater MTU.
Default value is **100**.
.. cfgcmd:: set vpn l2tp remote-access ppp-options mppe <require | prefer | deny>
Specifies :abbr:`MPPE (Microsoft Point-to-Point Encryption)` negotiation
preference.
* **require** - ask client for mppe, if it rejects drop connection
* **prefer** - ask client for mppe, if it rejects don't fail. (Default value)
* **deny** - deny mppe
Default behavior - don't ask client for mppe, but allow it if client wants.
Please note that RADIUS may override this option by MS-MPPE-Encryption-Policy
attribute.
.. cfgcmd:: set vpn l2tp remote-access ppp-options mru <number>
Defines preferred MRU. By default is not defined.
Global Advanced options
=======================
.. cfgcmd:: set vpn l2tp remote-access description <description>
Set description.
.. cfgcmd:: set vpn l2tp remote-access limits burst <value>
Burst count
.. cfgcmd:: set vpn l2tp remote-access limits connection-limit <value>
Acceptable rate of connections (e.g. 1/min, 60/sec)
.. cfgcmd:: set vpn l2tp remote-access limits timeout <value>
Timeout in seconds
.. cfgcmd:: set vpn l2tp remote-access mtu
Maximum Transmission Unit (MTU) (default: **1436**)
.. cfgcmd:: set vpn l2tp remote-access max-concurrent-sessions
Maximum number of concurrent session start attempts
.. cfgcmd:: set vpn l2tp remote-access name-server <address>
Connected client should use `<address>` as their DNS server. This
command accepts both IPv4 and IPv6 addresses. Up to two nameservers
can be configured for IPv4, up to three for IPv6.
.. cfgcmd:: set vpn l2tp remote-access shaper fwmark <1-2147483647>
Match firewall mark value
.. cfgcmd:: set vpn l2tp remote-access snmp master-agent
Enable SNMP
.. cfgcmd:: set vpn l2tp remote-access wins-server <address>
Windows Internet Name Service (WINS) servers propagated to client
**********
Monitoring
**********
.. code-block:: none
vyos@vyos:~$ show l2tp-server sessions
ifname | username | ip | ip6 | ip6-dp | calling-sid | rate-limit | state | uptime | rx-bytes | tx-bytes
--------+----------+---------------+-----+--------+-------------+------------+--------+----------+----------+----------
l2tp0 | test | 192.168.255.3 | | | 192.168.0.36 | | active | 02:01:47 | 7.7 KiB | 1.2 KiB
.. code-block:: none
vyos@vyos:~$ show l2tp-server statistics
uptime: 0.02:49:49
cpu: 0%
mem(rss/virt): 5920/100892 kB
core:
mempool_allocated: 133202
mempool_available: 131770
thread_count: 1
thread_active: 1
context_count: 5
context_sleeping: 0
context_pending: 0
md_handler_count: 3
md_handler_pending: 0
timer_count: 0
timer_pending: 0
sessions:
starting: 0
active: 0
finishing: 0
l2tp:
tunnels:
starting: 0
active: 0
finishing: 0
sessions (control channels):
starting: 0
active: 0
finishing: 0
sessions (data channels):
starting: 0
active: 0
finishing: 0
.. _`Google Public DNS`: https://developers.google.com/speed/public-dns
.. _Quad9: https://quad9.net
@ -230,3 +569,5 @@ renamed.
.. _FreeRADIUS: https://freeradius.org
.. _`Network Policy Server`: https://en.wikipedia.org/wiki/Network_Policy_Server
.. _accel-ppp: https://accel-ppp.org/
.. _dictionary: https://github.com/accel-ppp/accel-ppp/blob/master/accel-pppd/radius/dict/dictionary.rfc6911
.. _`ACCEL-PPP attribute`: https://github.com/accel-ppp/accel-ppp/blob/master/accel-pppd/radius/dict/dictionary.accel