Rewritten the PPTP server documentation

Fully rewritten PPTP server documentation.

1 files changed, 526 insertions, 26 deletions

diff --git a/docs/configuration/vpn/pptp.rst b/docs/configuration/vpn/pptp.rst
index fe536eec..2a5e7731 100644
--- a/docs/configuration/vpn/pptp.rst
+++ b/docs/configuration/vpn/pptp.rst
@@ -1,52 +1,552 @@
 .. _pptp:
 
+###########
 PPTP-Server
------------
+###########
 
 The Point-to-Point Tunneling Protocol (PPTP_) has been implemented in VyOS only
 for backwards compatibility. PPTP has many well known security issues and you 
 should use one of the many other new VPN implementations.
 
-As per default and if not otherwise defined, mschap-v2 is being used for
-authentication and mppe 128-bit (stateless) for encryption. If no
-gateway-address is set within the configuration, the lowest IP out of the /24
-client-ip-pool is being used. For instance, in the example below it would be
-192.168.0.1.
-
-server example
-^^^^^^^^^^^^^^
+***********************
+Configuring PPTP Server
+***********************
 
 .. code-block:: none
 
+  set vpn pptp remote-access authentication mode local
   set vpn pptp remote-access authentication local-users username test password 'test'
-  set vpn pptp remote-access authentication mode 'local'
-  set vpn pptp remote-access client-ip-pool PPTP-POOL range 192.168.0.10-192.168.0.15
+  set vpn pptp remote-access client-ip-pool PPTP-POOL range 192.168.255.2-192.168.255.254
   set vpn pptp remote-access default-pool 'PPTP-POOL'
-  set vpn pptp remote-access gateway-address '10.100.100.1'
-  set vpn pptp remote-access outside-address '10.1.1.120'
+  set vpn pptp remote-access outside-address 192.0.2.2
+  set vpn pptp remote-access gateway-address 192.168.255.1
+
+
+.. cfgcmd:: set vpn pptp 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.
+  * **noauth**: Authentication disabled.
+
+.. cfgcmd:: set vpn pptp 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 pptp 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 PPTP 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 pptp remote-access default-pool <POOL-NAME>
+
+   Use this command to define default address pool name.
+
+.. cfgcmd:: set vpn pptp remote-access gateway-address <gateway>
+
+  Specifies single `<gateway>` IP address to be used as local address of PPP
+  interfaces.
+
+*********************************
+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
+exists within the configuration, however they are not used if the mode has been
+changed from local to radius. Once changed back to local, it will use all local
+accounts again.
+
+.. code-block:: none
+
+  set vpn pptp remote-access authentication mode radius
+
+.. cfgcmd:: set vpn pptp 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
+
+  set vpn pptp remote-access authentication radius server 10.0.0.1 key 'foo'
+  set vpn pptp remote-access authentication radius server 10.0.0.2 key 'foo'
+
+.. note:: Some RADIUS severs use an access control list which allows or denies
+   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. You can bind all outgoing RADIUS requests
+to a single source IP e.g. the loopback interface.
+
+.. cfgcmd:: set vpn pptp remote-access authentication radius source-address <address>
+
+  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 advanced options
+=======================
+
+.. cfgcmd:: set vpn pptp remote-access authentication radius server <server> port <port>
+
+  Configure RADIUS `<server>` and its required port for authentication requests.
+
+.. cfgcmd:: set vpn pptp remote-access authentication radius server <server> fail-time <time>
+
+  Mark RADIUS server as offline for this given `<time>` in seconds.
+
+.. cfgcmd:: set vpn pptp remote-access authentication radius server <server> disable
+
+  Temporary disable this RADIUS server.
+
+.. cfgcmd:: set vpn pptp remote-access authentication radius acct-timeout <timeout>
+
+  Timeout to wait reply for Interim-Update packets. (default 3 seconds)
+
+.. cfgcmd:: set vpn pptp remote-access authentication radius dynamic-author server <address>
+
+  Specifies IP address for Dynamic Authorization Extension server (DM/CoA)
+
+.. cfgcmd:: set vpn pptp remote-access authentication radius dynamic-author port <port>
+
+  Port for Dynamic Authorization Extension server (DM/CoA)
+
+.. cfgcmd:: set vpn pptp remote-access authentication radius dynamic-author key <secret>
+
+  Secret for Dynamic Authorization Extension server (DM/CoA)
+
+.. cfgcmd:: set vpn pptp remote-access authentication radius max-try <number>
+
+  Maximum number of tries to send Access-Request/Accounting-Request queries
+
+.. cfgcmd:: set vpn pptp remote-access authentication radius timeout <timeout>
+
+  Timeout to wait response from server (seconds)
+
+.. cfgcmd:: set vpn pptp 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 pptp 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 pptp remote-access authentication radius source-address <address>
+
+  Source IPv4 address used in all RADIUS server queires.
+
+.. cfgcmd:: set vpn pptp 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.
+
+.. cfgcmd:: set vpn pptp remote-access authentication radius rate-limit enable
+
+  Enables bandwidth shaping via RADIUS.
+
+.. cfgcmd:: set vpn pptp 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 ``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.
+
+.. note:: The value of the attribute ``NAS-Port-Id`` must be less than 16
+   characters, otherwise the interface won't be renamed.
+
+****
+IPv6
+****
+.. cfgcmd:: set vpn pptp 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 pptp 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 PPTP client
+  will get an IPv6 prefix of your defined length (mask) to terminate the
+  PPTP endpoint at their side. The mask length can be set from 48 to 128
+  bit long, the default value is 64.
+
+.. cfgcmd:: set vpn pptp 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
+  PPTP. 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 pptp remote-access default-ipv6-pool <IPv6-POOL-NAME>
 
+   Use this command to define default IPv6 address pool name.
 
-client example (debian 9)
-^^^^^^^^^^^^^^^^^^^^^^^^^
+.. code-block:: none
+
+  set vpn pptp remote-access ppp-options ipv6 allow
+  set vpn pptp remote-access client-ipv6-pool IPv6-POOL delegate '2001:db8:8003::/48' delegation-prefix '56'
+  set vpn pptp remote-access client-ipv6-pool IPV6-POOL prefix '2001:db8:8002::/48' mask '64'
+  set vpn pptp remote-access default-ipv6-pool IPv6-POOL
+
+IPv6 Advanced Options
+=====================
+.. cfgcmd:: set vpn pptp remote-access ppp-options ipv6-accept-peer-interface-id
+
+  Accept peer interface identifier. By default is not defined.
+
+.. cfgcmd:: set vpn pptp 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 pptp 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 pptp remote-access extended-scripts on-change <path_to_script>
+
+  Script to run when session interface changed by RADIUS CoA handling
+
+.. cfgcmd:: set vpn pptp remote-access extended-scripts on-down <path_to_script>
+
+  Script to run when session interface going to terminate
+
+.. cfgcmd:: set vpn pptp remote-access extended-scripts on-pre-up <path_to_script>
+
+  Script to run before session interface comes up
+
+.. cfgcmd:: set vpn pptp 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 pptp remote-access authentication local-users username <user> disable
+
+  Disable `<user>` account.
+
+.. cfgcmd:: set vpn pptp remote-access authentication local-users username <user> static-ip
+   <address>
+
+  Assign static IP address to `<user>` account.
+
+.. cfgcmd:: set vpn pptp remote-access authentication local-users username <user> rate-limit
+   download <bandwidth>
+
+  Download bandwidth limit in kbit/s for `<user>`.
+
+.. cfgcmd:: set vpn pptp remote-access authentication local-users username <user> rate-limit
+   upload <bandwidth>
+
+  Upload bandwidth limit in kbit/s for `<user>`.
+
+.. cfgcmd:: set vpn pptp 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 pptp 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 pptp remote-access ppp-options disable-ccp
+
+  Disable Compression Control Protocol (CCP).
+  CCP is enabled by default.
+
+.. cfgcmd:: set vpn pptp 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 pptp remote-access ppp-options ipv4 <require | prefer | allow | deny>
+
+  Specifies IPv4 negotiation preference.
 
-Install the client software via apt and execute pptpsetup to generate the
-configuration.
+  * **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 pptp 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 pptp 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 pptp 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 pptp 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 pptp 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 pptp remote-access ppp-options mru <number>
+
+  Defines preferred MRU. By default is not defined.
+
+Global Advanced options
+=======================
+
+.. cfgcmd:: set vpn pptp remote-access description <description>
+
+  Set description.
+
+.. cfgcmd::  set vpn pptp remote-access limits burst <value>
+
+  Burst count
+
+.. cfgcmd:: set vpn pptp remote-access limits connection-limit <value>
+
+  Acceptable rate of connections (e.g. 1/min, 60/sec)
+
+.. cfgcmd:: set vpn pptp remote-access limits timeout <value>
+
+  Timeout in seconds
+
+.. cfgcmd:: set vpn pptp remote-access mtu
+
+  Maximum Transmission Unit (MTU) (default: **1436**)
+
+.. cfgcmd:: set vpn pptp remote-access max-concurrent-sessions
+
+  Maximum number of concurrent session start attempts
+
+.. cfgcmd:: set vpn pptp 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 pptp remote-access shaper fwmark <1-2147483647>
+
+  Match firewall mark value
+
+.. cfgcmd:: set vpn pptp remote-access snmp master-agent
+
+  Enable SNMP
+
+.. cfgcmd:: set vpn pptp remote-access wins-server <address>
+
+  Windows Internet Name Service (WINS) servers propagated to client
+
+**********
+Monitoring
+**********
+
+.. opcmd:: show pptp-server sessions
+
+   Use this command to locally check the active sessions in the PPTP
+   server.
 
 .. code-block:: none
 
-  apt-get install pptp-linux
-  pptpsetup --create TESTTUNNEL --server 10.1.1.120 --username test --password test --encrypt
-  pon TESTTUNNEL
+    vyos@vyos:~$ show pptp-server sessions
+     ifname | username |    ip    | ip6 | ip6-dp |   calling-sid  | rate-limit | state  |  uptime  | rx-bytes | tx-bytes
+    --------+----------+----------+-----+--------+----------------+------------+--------+----------+----------+----------
+     pptp0  | test     | 10.0.0.2 |     |        | 192.168.10.100 |            | active | 00:01:26 | 6.9 KiB  | 220 B
 
-The command pon TESTUNNEL establishes the PPTP tunnel to the remote system.
+.. code-block:: none
 
+    vyos@vyos:~$ show pptp-server statistics
+     uptime: 0.00:04:52
+    cpu: 0%
+    mem(rss/virt): 5504/100176 kB
+    core:
+      mempool_allocated: 152007
+      mempool_available: 149007
+      thread_count: 1
+      thread_active: 1
+      context_count: 6
+      context_sleeping: 0
+      context_pending: 0
+      md_handler_count: 6
+      md_handler_pending: 0
+      timer_count: 2
+      timer_pending: 0
+    sessions:
+      starting: 0
+      active: 1
+      finishing: 0
+    pptp:
+      starting: 0
+      active: 1
 
-All tunnel sessions can be checked via:
+***************
+Troubleshooting
+***************
 
 .. code-block:: none
 
-  run sh pptp-server sessions
-   ifname | username | calling-sid |      ip      | type | comp | state  |  uptime
-  --------+----------+-------------+--------------+------+------+--------+----------
-   ppp0   | test     | 10.1.1.99   | 192.168.0.10 | pptp | mppe | active | 00:00:58
+    vyos@vyos:~$sudo journalctl -u accel-ppp@pptp -b 0
+
+    Feb 29 14:58:57 vyos accel-pptp[4629]: pptp: new connection from 192.168.10.100
+    Feb 29 14:58:57 vyos accel-pptp[4629]: :: recv [PPTP Start-Ctrl-Conn-Request <Version 1> <Framing 1> <Bearer 1> <Max-Chan 0>]
+    Feb 29 14:58:57 vyos accel-pptp[4629]: :: send [PPTP Start-Ctrl-Conn-Reply <Version 1> <Result 1> <Error 0> <Framing 3> <Bearer 3> <Max-Chan 1>]
+    Feb 29 14:58:57 vyos accel-pptp[4629]: :: recv [PPTP Outgoing-Call-Request <Call-ID 2961> <Call-Serial 2> <Min-BPS 300> <Max-BPS 100000000> <Bearer 3> <Framing 3> <Window-Size 64> <Delay 0>]
+    Feb 29 14:58:57 vyos accel-pptp[4629]: :: send [PPTP Outgoing-Call-Reply <Call-ID 2> <Peer-Call-ID 2961> <Result 1> <Error 0> <Cause 0> <Speed 100000000> <Window-Size 64> <Delay 0> <Channel 0>]
+    Feb 29 14:58:57 vyos accel-pptp[4629]: :: lcp_layer_init
+    Feb 29 14:58:57 vyos accel-pptp[4629]: :: auth_layer_init
+    Feb 29 14:58:57 vyos accel-pptp[4629]: :: ccp_layer_init
+    Feb 29 14:58:57 vyos accel-pptp[4629]: :: ipcp_layer_init
+    Feb 29 14:58:57 vyos accel-pptp[4629]: :: ipv6cp_layer_init
+    Feb 29 14:58:57 vyos accel-pptp[4629]: :: ppp establishing
+    Feb 29 14:58:57 vyos accel-pptp[4629]: :: lcp_layer_start
+    Feb 29 14:58:57 vyos accel-pptp[4629]: :: send [LCP ConfReq id=75 <auth PAP> <mru 1436> <magic 483920bd>]
+    Feb 29 14:58:57 vyos accel-pptp[4629]: :: recv [PPTP Set-Link-Info]
+    Feb 29 14:58:57 vyos accel-pptp[4629]: :: recv [LCP ConfReq id=0 <mru 1400> <magic 0142785a> <pcomp> <accomp> < d 3 6 >]
+    Feb 29 14:58:57 vyos accel-pptp[4629]: :: send [LCP ConfRej id=0 <pcomp> <accomp> < d 3 6 >]
+    Feb 29 14:58:57 vyos accel-pptp[4629]: :: recv [LCP ConfReq id=1 <mru 1400> <magic 0142785a>]
+    Feb 29 14:58:57 vyos accel-pptp[4629]: :: send [LCP ConfAck id=1]
+    Feb 29 14:59:00 vyos accel-pptp[4629]: :: fsm timeout 9
+    Feb 29 14:59:00 vyos accel-pptp[4629]: :: send [LCP ConfReq id=75 <auth PAP> <mru 1436> <magic 483920bd>]
+    Feb 29 14:59:00 vyos accel-pptp[4629]: :: recv [LCP ConfNak id=75 <auth MSCHAP-v2>]
+    Feb 29 14:59:00 vyos accel-pptp[4629]: :: send [LCP ConfReq id=76 <auth CHAP-md5> <mru 1436> <magic 483920bd>]
+    Feb 29 14:59:00 vyos accel-pptp[4629]: :: recv [LCP ConfNak id=76 <auth MSCHAP-v2>]
+    Feb 29 14:59:00 vyos accel-pptp[4629]: :: send [LCP ConfReq id=77 <auth MSCHAP-v1> <mru 1436> <magic 483920bd>]
+    Feb 29 14:59:00 vyos accel-pptp[4629]: :: recv [LCP ConfNak id=77 <auth MSCHAP-v2>]
+    Feb 29 14:59:00 vyos accel-pptp[4629]: :: send [LCP ConfReq id=78 <auth MSCHAP-v2> <mru 1436> <magic 483920bd>]
+    Feb 29 14:59:00 vyos accel-pptp[4629]: :: recv [LCP ConfAck id=78 <auth MSCHAP-v2> <mru 1436> <magic 483920bd>]
+    Feb 29 14:59:00 vyos accel-pptp[4629]: :: lcp_layer_started
+    Feb 29 14:59:00 vyos accel-pptp[4629]: :: auth_layer_start
+    Feb 29 14:59:00 vyos accel-pptp[4629]: :: send [MSCHAP-v2 Challenge id=1 <8aa758781676e6a8e85c11963ee010>]
+    Feb 29 14:59:00 vyos accel-pptp[4629]: :: recv [LCP Ident id=2 <MSRASV5.20>]
+    Feb 29 14:59:00 vyos accel-pptp[4629]: :: recv [LCP Ident id=3 <MSRAS-0-MSEDGEWIN10>]
+    Feb 29 14:59:00 vyos accel-pptp[4629]: [43B blob data]
+    Feb 29 14:59:00 vyos accel-pptp[4629]: :: recv [PPTP Set-Link-Info]
+    Feb 29 14:59:00 vyos accel-pptp[4629]: :: recv [MSCHAP-v2 Response id=1 <90c21af1091f745e8bf22388b058>, <e695ae5aae274c88a3fa1ee3dc9057aece4d53c87b9fea>, F=0, name="test"]
+    Feb 29 14:59:00 vyos accel-pptp[4629]: ppp0:test: connect: ppp0 <--> pptp(192.168.10.100)
+    Feb 29 14:59:00 vyos accel-pptp[4629]: ppp0:test: ppp connected
+    Feb 29 14:59:00 vyos accel-pptp[4629]: ppp0:test: send [MSCHAP-v2 Success id=1 "S=347F417CF04BEBBC7F75CFA7F43474C36FB218F9 M=Authentication succeeded"]
+    Feb 29 14:59:00 vyos accel-pptp[4629]: ppp0:test: test: authentication succeeded
+    Feb 29 14:59:00 vyos accel-pptp[4629]: ppp0:test: auth_layer_started
+    Feb 29 14:59:00 vyos accel-pptp[4629]: ppp0:test: ccp_layer_start
+    Feb 29 14:59:00 vyos accel-pptp[4629]: ppp0:test: send [CCP ConfReq id=b9 <mppe +H -M +S -L -D -C>]
+    Feb 29 14:59:00 vyos accel-pptp[4629]: ppp0:test: ipcp_layer_start
+    Feb 29 14:59:00 vyos accel-pptp[4629]: ppp0:test: ipv6cp_layer_start
+    Feb 29 14:59:00 vyos accel-pptp[4629]: ppp0:test: IPV6CP: discarding packet
+    Feb 29 14:59:00 vyos accel-pptp[4629]: ppp0:test: send [LCP ProtoRej id=122 <8057>]
+    Feb 29 14:59:00 vyos accel-pptp[4629]: ppp0:test: recv [IPCP ConfReq id=6 <addr 0.0.0.0> <dns1 0.0.0.0> <wins1 0.0.0.0> <dns2 0.0.0.0> <wins2 0.0.0.0>]
+    Feb 29 14:59:00 vyos accel-pptp[4629]: ppp0:test: send [IPCP ConfReq id=3b <addr 10.0.0.1>]
+    Feb 29 14:59:00 vyos accel-pptp[4629]: ppp0:test: send [IPCP ConfRej id=6 <dns1 0.0.0.0> <wins1 0.0.0.0> <dns2 0.0.0.0> <wins2 0.0.0.0>]
+    Feb 29 14:59:00 vyos accel-pptp[4629]: ppp0:test: recv [LCP ProtoRej id=7 <80fd>]
+    Feb 29 14:59:00 vyos accel-pptp[4629]: ppp0:test: ccp_layer_finished
+    Feb 29 14:59:00 vyos accel-pptp[4629]: ppp0:test: recv [IPCP ConfAck id=3b <addr 10.0.0.1>]
+    Feb 29 14:59:00 vyos accel-pptp[4629]: ppp0:test: recv [IPCP ConfReq id=8 <addr 0.0.0.0>]
+    Feb 29 14:59:00 vyos accel-pptp[4629]: ppp0:test: send [IPCP ConfNak id=8 <addr 10.0.0.2>]
+    Feb 29 14:59:00 vyos accel-pptp[4629]: ppp0:test: recv [IPCP ConfReq id=9 <addr 10.0.0.2>]
+    Feb 29 14:59:00 vyos accel-pptp[4629]: ppp0:test: send [IPCP ConfAck id=9]
+    Feb 29 14:59:00 vyos accel-pptp[4629]: ppp0:test: ipcp_layer_started
+    Feb 29 14:59:00 vyos accel-pptp[4629]: ppp0:test: rename interface to 'pptp0'
+    Feb 29 14:59:00 vyos accel-pptp[4629]: pptp0:test: pptp: ppp started
+
+.. _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