3Com OfficeConnect 3CR856-95 User Manual

Also see for OfficeConnect 3CR856-95: Installation guide User guide

Contents

50between two devices, to ensure that everything is workingcorrectly.By default the Gateway has PING disabled so that it does notrespond to PING requests. This makes the device more difficult tofind on the Internet and less prone to attack.This feature is enabled by clicking on the check box so that a tickcan be seen and then pressing the Apply button.3Com recommends that you leave Allow PING from the Internetdisabled as this provides greater security.Disable Firewall The Gateway contains a firewall that detectsattack patterns used by hackers on the Internet and oncedetected will block their access to your network. The Firewall isdisabled by clicking on the check box so that a tick can be seenand then pressing the Apply button.3Com recommends that you leave the firewall enabled (checkboxcleared) for normal use. You may wish to turn it off fordiagnostic purposes.Configuring VPNVirtual Private Networks (VPNs) are secure tunnels betweennetworks or between a network and a user. The Gatewaysupports both network to network connection and network touser connections.Your Cable/DSL modem and your ISP must support IPSec or PPTPpass-through for you to be able to use these protocols.The Gateway supports both IPSec tunnels and PPTP connectionsand allows VPN pass-through to enable other secure devices onyour network to set up their own secure connections.See “The Virtual Servers Menu” on page 43 for details toconfigure pass-through protocols.Setting the VPN ModeThe Gateway supports three modes of VPN operation: Disable VPNs IPSec Enabled PPTP Server EnabledEnabling IPSec VPN will disable IPSec pass-through. Enabling thePPTP server will disable PPTP pass-through.A VPN Tunnel needs the same protocol on both sides of theconnection. If you are trying to establish an IPSec connectionwith another Gateway or with a user the other Gateway mustsupport IPSec or the user must have software installed thatsupports IPSec VPN.The VPN Mode menu is shown in Figure 47 below. Choose oneof the options by clicking in the appropriate radio button.dua08569-5aaa01.book Page 50 Wednesday, March 13, 2002 10:39 AM