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Overview

RouterOS supports Point-to-Point Tunneling Protocol (PPTP) which is one of the obsolete methods for implementing a VPN.

Introduction

PPTP has many known security issues and we are not recommending to use it. However, this protocol is integrated into common operating systems and it is easy to set it up. PPTP can be useful in networks where security concerns are not considered.

PPTP traffic uses TCP port 1723 and IP protocol GRE (Generic Routing Encapsulation, IP protocol ID 47), as assigned by the Internet Assigned Numbers Authority (IANA). PPTP can be used with most firewalls and routers by enabling traffic destined for TCP port 1723 and protocol 47 traffic to be routed through the firewall or router.  PPTP includes PPP authentication and accounting for each PPTP connection. Full authentication and accounting of each connection may be done through a RADIUS client or locally.

PPTP Server

/interface pptp-server

An interface is created for each tunnel established to the given server. There are two types of interfaces in the L2TP server's configuration:

  • Static interfaces are added administratively if there is a need to reference the particular interface name (in firewall rules or elsewhere) created for the particular user;
  • Dynamic interfaces are added to this list automatically whenever a user is connected and its username does not match any existing static entry (or in case the entry is active already, as there can not be two separate tunnel interfaces referenced by the same name);

Dynamic interfaces appear when a user connects and disappear once the user disconnects, so it is impossible to reference the tunnel created for that use in router configuration (for example, in firewall), so if you need persistent rules for that user, create a static entry for him/her. Otherwise, it is safe to use a dynamic configuration.

In both cases PPP users must be configured properly - static entries do not replace PPP configuration.

Access Concentrator

[admin@MikroTik] > interface pptp-server server

The PPTP server (access concentrator) supports multiple servers for each interface - with differing service names. The access concentrator name and PPTP service name are used by clients to identify the access concentrator to register with. The access concentrator name is the same as the identity of the router displayed before the command prompt. The identity may be set within the /system identity submenu.

To enable the PPTP server:

[admin@MikroTik] > interface pptp-server server set enabled=yes
[admin@MikroTik] > interface pptp-server server print 
enabled: yes
max-mtu: 1450
max-mru: 1450
mrru: disabled
authentication: mschap1,mschap2
keepalive-timeout: 30
default-profile: default-encryption


Quick Example

PPTP Client

The following example demonstrates how to set up a PPTP client with username "MT-User", password "StrongPass" and server 192.168.62.2:


[admin@MikroTik] > interface pptp-client add connect-to=192.168.62.2 disabled=no name=pptp-out1 password=StrongPass user=MT-User
[admin@MikroTik] > interface pptp-client print 
Flags: X - disabled; R - running 
 0  R name="pptp-out1" max-mtu=1450 max-mru=1450 mrru=disabled connect-to=192.168.62.2 user="MT-User" 
      password="StrongPass" profile=default-encryption keepalive-timeout=60 add-default-route=no 
      dial-on-demand=no allow=pap,chap,mschap1,mschap2 

PPTP Server

On the other side we simply enable the PPTP server and create a PPP secret for a particular user:

[admin@MikroTik] >  interface pptp-server server set enabled=yes
[admin@MikroTik] >  ppp secret add local-address=10.0.0.1 name=MT-User password=StrongPass profile=default-encryption remote-address=10.0.0.5 service=pptp
[admin@MikroTik] >  interface pptp-server print
Flags: D - dynamic; R - running
Columns: NAME, USER, MTU, CLIENT-ADDRESS, UPTIME, ENCODING
#      NAME            USER     MTU  CLIENT-ADDRESS  UPTIM  ENCODING         
0  DR  <pptp-MT-User>  MT-User  1450  192.168.51.3   44m8s  MPPE128 stateless




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