Motorola MT7711 User Manual page 68

In the implementation of PPTP and L2TP on the MT7711, MPPE
encryption is optional. Both protocols require a login; L2TP requires a
passkey for authentication.
There are three pages under VPN in the MT7711 configuration manager:
IPsec, L2TP/PPTP and Event Log. Use the IPsec page to set up an
endpoint for a site to site IPsec connection. Use the PPTP/L2TP page to
set up a server for a set of remote clients that connect via PPTP or L2TP.
You may find the Event Log useful to determine what has gone wrong if
you have trouble setting up a VPN.
For details on how to configure a VPN on the MT7711, follow the help
available through the information icons on the configuration manager
pages.
When the MT7711 is configured as a VPN endpoint, devices that connect
to the endpoint will need to know the IP Address of the MT7711. You can
find this address on the Status  Connections page. To provide the most
stable VPN connections, the MT7711's router should be provisioned with
a static IP Address. You will need to order this from your cable service
provider.
The VPN implementations on the MT7711 are best effort. They are also
Windows-centric. You will have to verify suitability for your own environment.
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