P-660 Series Support Notes 
  4.          0            0          0.0.0.0 
  5.          0            0          0.0.0.0 
  6.          0            0          0.0.0.0 
  7.          0            0          0.0.0.0 
  8.          0            0          0.0.0.0 
  9.          0            0          0.0.0.0 
  10.          0            0     0.0.0.0 
  11.          0            0     0.0.0.0 
  12.          0            0     0.0.0.0   
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The most often used port numbers are shown in the following table. Please refer RFC 
1700 for further information about port numbers.   
   
Service  Port Number 
FTP 21 
Telnet 23 
SMTP 25 
DNS (Domain Name Server)  53 
www-http (Web)  80 
PPTP (Point-to-Point Tunneling 
Protocol) 
1723 
Examples  
•  Internet Access Only   
•  Internet Access with an Internal Server   
•  Using Multiple Global IP addresses for clients and servers   
•  Support Non NAT Friendly Applications   
1. Internet Access Only   
In our Internet Access example, we only need one rule where all our ILAs map to one 
IGA assigned by the ISP. See the following figure.   
 
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