Pptp example – Netopia 4553 User Manual
Page 144

10-144 User’s Reference Guide
PPTP example
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.
Display/Change Input Filter screen
Select Input Filter 1 and press Return. In the Change Input Filter 1 screen, set the Destination Por t information 
as shown below.
Select Input Filter 2 and press Return. In the Change Input Filter 2 screen, set the Protocol Type to allow GRE 
as shown below.
Main
Menu
System
Filter
Sets
Display/Change
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 =2000 Yes No |
 | 2 0.0.0.0 0.0.0.0 TCP NC =6000 Yes No |
 | |
 +---------------------------------------------------------------------------+
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
