User guide
Introduction
1-3
• Security
The CheetahAccess Internet Gateway supports security features that 
can deny Internet access to specified users, or filter all requests for 
specific services the administrator does not want to serve. The 
CheetahAccess Internet Gateway’s firewall can also block common 
hacker attacks, including IP Spoofing, Land Attack, Ping of Death, IP 
with zero length, Smurf Attack, UDP port loopback, Snork Attack, TCP 
null scan, and TCP SYN flooding.
• Virtual Private Network
The CheetahAccess Internet Gateway supports three of the most 
commonly used VPN protocols – PPTP, L2TP and IPSec. These 
protocols allow remote users to establish a secure connection to their 
corporate network. If your service provider supports VPNs, then any of 
these protocols can be used to create an authenticated and encrypted 
tunnel for passing secure data over the Internet (i.e., a traditionally 
shared data network). The VPN protocols supported by the 
CheetahAccess Internet Gateway are briefly described below.
• Point-to-Point Tunneling Protocol – Provides a secure tunnel for 
remote client access to a PPTP security gateway. PPTP includes 
provisions for call origination and flow control required by ISPs.
• Layer Two Tunneling Protocol – Includes most of the features 
provided by PPTP, but has less overhead and is more suited for 
managed networks.
• IP Security – Provides IP network-layer encryption. IPSec can 
support large encryption networks (such as the Internet) by using 
digital certificates for device authentication. 










