Справочное Руководство для Netopia r6100

To enable a firewall to allow PPTP traffic, you must provision the firewall to allow inbound and outbound TCP 
packets specifically destined for por t 1723. The source por t may be dynamic, so often it is not useful to apply 
a compare function upon this por tion of the control/negotiation packets. You must also set the firewall to allow 
inbound and outbound GRE packets, enabling transpor t of the tunnel payload.

From the Main Menu navigate to Display/Change IP Filter Set, and from the pop-up menu select Basic Firewall.

Select Display/Change Input Filter.

For Input Filter 1 set the Destination Por t information as shown below.

Main

Menu

System

Filter

Sets

IP Filter

Sets

Display/Change

IP Filter Set

Configuration

Basic

Firewall

   +-#----Source IP Addr----Dest IP Addr------Proto-Src.Port-D.Port--On?-Fwd-+
   +-------------------------------------------------------------------------+
   | 1    0.0.0.0           0.0.0.0           TCP   NC       =1723   Yes Yes |
   | 2    0.0.0.0           0.0.0.0           GRE   --       --      Yes Yes |
   |                                                                         |

                            Change Input Filter 1  

         Enabled:                           Yes
         Forward:                           Yes

         Source IP Address:                 0.0.0.0
         Source IP Address Mask:            0.0.0.0

         Dest. IP Address:                  0.0.0.0
         Dest. IP Address Mask:             0.0.0.0

         Protocol Type:                     TCP
         Source Port Compare...             No Compare
         Source Port ID:                    0
         Dest. Port Compare...              Equal
         Dest. Port ID:                     1723
         Established TCP Conns. Only:       No