The following is an example of connecting two Intranets using an encrypted PPTP tunnel over the Internet. 
There are two routers in this example:
- [HomeOffice]
Interface LocalHomeOffice 10.150.2.254/24
Interface ToInternet 192.168.80.1/24 - [RemoteOffice]
Interface ToInternet 192.168.81.1/24
Interface LocalRemoteOffice 10.150.1.254/24
Each router is connected to a different ISP. One router can access another router through the Internet. On the PPTP server a user must be set up for the client:
[admin@HomeOffice] ppp secret> add name=ex service=pptp password=lkjrht
local-address=10.0.103.1 remote-address=10.0.103.2
[admin@HomeOffice] ppp secret> print detail
Flags: X - disabled
0 name="ex" service=pptp caller-id="" password="lkjrht" profile=default
local-address=10.0.103.1 remote-address=10.0.103.2 routes==""
[admin@HomeOffice] ppp secret>
Then the user should be added in the PPTP server list:
[admin@HomeOffice] interface pptp-server> add user=ex [admin@HomeOffice] interface pptp-server> print Flags: X - disabled, D - dynamic, R - running # NAME USER MTU CLIENT-ADDRESS UPTIME ENC... 0 pptp-in1 ex [admin@HomeOffice] interface pptp-server>
And finally, the server must be enabled:
[admin@HomeOffice] interface pptp-server server> set enabled=yes
[admin@HomeOffice] interface pptp-server server> print
enabled: yes
mtu: 1460
mru: 1460
authentication: mschap2
default-profile: default
[admin@HomeOffice] interface pptp-server server>
Add a PPTP client to the RemoteOffice router:
[admin@RemoteOffice] interface pptp-client> add connect-to=192.168.80.1 user=ex \
\... password=lkjrht disabled=no
[admin@RemoteOffice] interface pptp-client> print
Flags: X - disabled, R - running
0 R name="pptp-out1" mtu=1460 mru=1460 connect-to=192.168.80.1 user="ex"
password="lkjrht" profile=default add-default-route=no
[admin@RemoteOffice] interface pptp-client>
Thus, a PPTP tunnel is created between the routers. This tunnel is like an Ethernet point-to-point connection between the routers with IP addresses 10.0.103.1 and 10.0.103.2 at each router. It enables ‘direct’ communication between the routers over third party networks.
To route the local Intranets over the PPTP tunnel – add these routes:
[admin@HomeOffice] > ip route add dst-address 10.150.1.0/24 gateway 10.0.103.2 [admin@RemoteOffice] > ip route add dst-address 10.150.2.0/24 gateway 10.0.103.1
On the PPTP server it can alternatively be done using routes parameter of the user configuration:
[admin@HomeOffice] ppp secret> print detail
Flags: X - disabled
0 name="ex" service=pptp caller-id="" password="lkjrht" profile=default
local-address=10.0.103.1 remote-address=10.0.103.2 routes==""
[admin@HomeOffice] ppp secret> set 0 routes="10.150.1.0/24 10.0.103.2 1"
[admin@HomeOffice] ppp secret> print detail
Flags: X - disabled
0 name="ex" service=pptp caller-id="" password="lkjrht" profile=default
local-address=10.0.103.1 remote-address=10.0.103.2
routes="10.150.1.0/24 10.0.103.2 1"
[admin@HomeOffice] ppp secret>
Test the PPTP tunnel connection:
[admin@RemoteOffice]> /ping 10.0.103.1 10.0.103.1 pong: ttl=255 time=3 ms 10.0.103.1 pong: ttl=255 time=3 ms 10.0.103.1 pong: ttl=255 time=3 ms ping interrupted 3 packets transmitted, 3 packets received, 0% packet loss round-trip min/avg/max = 3/3.0/3 ms
Test the connection through the PPTP tunnel to the LocalHomeOffice interface:
[admin@RemoteOffice]> /ping 10.150.2.254 10.150.2.254 pong: ttl=255 time=3 ms 10.150.2.254 pong: ttl=255 time=3 ms 10.150.2.254 pong: ttl=255 time=3 ms ping interrupted 3 packets transmitted, 3 packets received, 0% packet loss round-trip min/avg/max = 3/3.0/3 ms
To bridge a LAN over this secure tunnel, please see the example in the ‘EoIP’ section of the manual. To set the maximum speed for traffic over this tunnel, please consult the ‘Queues’ section.
Connecting a Remote Client via PPTP Tunnel
The following example shows how to connect a computer to a remote office network over PPTP encrypted tunnel giving that computer an IP address from the same network as the remote office has (without need of bridging over eoip tunnels) Please, consult the respective manual on how to set up a PPTP client with the software You are using.
The router in this example:
- [RemoteOffice]
Interface ToInternet 192.168.81.1/24
Interface Office 10.150.1.254/24
The client computer can access the router through the Internet. On the PPTP server a user must be set up for the client:
[admin@RemoteOffice] ppp secret> add name=ex service=pptp password=lkjrht
local-address=10.150.1.254 remote-address=10.150.1.2
[admin@RemoteOffice] ppp secret> print detail
Flags: X - disabled
0 name="ex" service=pptp caller-id="" password="lkjrht" profile=default
local-address=10.150.1.254 remote-address=10.150.1.2 routes==""
[admin@RemoteOffice] ppp secret>
Then the user should be added in the PPTP server list:
[admin@RemoteOffice] interface pptp-server> add name=FromLaptop user=ex [admin@RemoteOffice] interface pptp-server> print Flags: X - disabled, D - dynamic, R - running # NAME USER MTU CLIENT-ADDRESS UPTIME ENC... 0 FromLaptop ex [admin@RemoteOffice] interface pptp-server>
And the server must be enabled:
[admin@RemoteOffice] interface pptp-server server> set enabled=yes
[admin@RemoteOffice] interface pptp-server server> print
enabled: yes
mtu: 1460
mru: 1460
authentication: mschap2
default-profile: default
[admin@RemoteOffice] interface pptp-server server>
Finally, the proxy APR must be enabled on the ‘Office’ interface:
[admin@RemoteOffice] interface ethernet> set Office arp=proxy-arp [admin@RemoteOffice] interface ethernet> print Flags: X - disabled, R - running # NAME MTU MAC-ADDRESS ARP 0 R ToInternet 1500 00:30:4F:0B:7B:C1 enabled 1 R Office 1500 00:30:4F:06:62:12 proxy-arp [admin@RemoteOffice] interface ethernet>
PPTP Setup for Windows
Microsoft provides PPTP client support for Windows NT, 2000, ME, 98se, and 98. Windows 98se, 2000, and ME include support in the Windows setup or automatically install PPTP. For 95, NT, and 98, installation requires a download from Microsoft. Many ISPs have made help pages to assist clients with Windows PPTP installation. http://www.real-time.com/Customer_Support/PPTP_Config/pptp_config.html
http://www.microsoft.com/windows95/downloads/contents/WUAdminTools/S_WUNetworkingTools/W95WinsockUpgrade/Default.asp
Sample instructions for PPTP (VPN) installation and client setup – Windows 98se
If the VPN (PPTP) support is installed, select ‘Dial-up Networking’ and ‘Create a new connection’. The option to create a ‘VPN’ should be selected. If there is no ‘VPN’ options, then follow the installation instructions below. When asked for the ‘Host name or IP address of the VPN server’, type the IP address of the router. Double-click on the ‘new’ icon and type the correct user name and password (must also be in the user database on the router or RADIUS server used for authentication).
The setup of the connections takes nine seconds after selection the ‘connect’ button. It is suggested that the connection properties be edited so that ‘NetBEUI’, ‘IPX/SPX compatible’, and ‘Log on to network’ are unselected. The setup time for the connection will then be two seconds after the ‘connect’ button is selected.
To install the ‘Virtual Private Networking’ support for Windows 98se, go to the ‘Setting’ menu from the main ‘Start’ menu. Select ‘Control Panel’, select ‘Add/Remove Program’, select the ‘Windows setup’ tab, select the ‘Communications’ software for installation and ‘Details’. Go to the bottom of the list of software and select ‘Virtual Private Networking’ to be installed.
