EnGenius Technologies ESR-9710 Manual Do Utilizador

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ESR-9710 Wireless N Gigabit Router  
 
 
 
 
                         Version 1.0 
 
 
 58 
 
6.3.10 Firewall 
ƒ  The device provides a tight firewall by virtue of the way NAT works. Unless you 
configure the router to the contrary, the NAT does not respond to unsolicited 
incoming requests on any port, thereby making your LAN invisible to Internet cyber 
attacks. However, some network applications cannot run with a tight firewall. Those 
applications need to selectively open ports in the firewall to function correctly. The 
options on this page control several ways of opening the firewall to address the 
needs of specific types of applications. 
 
 
 
ƒ  Enable SPI: Place a check in this box to enable SPI. SPI ("stateful packet 
inspection" also known as "dynamic packet filtering") helps to prevent cyberattacks 
by tracking more state per session. It validates that the traffic passing through that 
session conforms to the protocol. When the protocol is TCP, SPI checks that packet 
sequence numbers are within the valid range for the session, discarding those 
packets that do not have valid sequence numbers. Whether SPI is enabled or not, 
the router always tracks TCP connection states and ensures that each TCP packet's 
flags are valid for the current state.  
ƒ  TCP / UDP NAT Endpoint Filtering options control how the router's NAT manages 
incoming connection requests to ports that are already being used. Select one of the 
radio buttons.  
o
  End Point Independent Once a LAN-side application has created a 
connection through a specific port, the NAT will forward any incoming 
connection requests with the same port to the LAN-side application 
regardless of their origin. This is the least restrictive option, giving the best 
connectivity and allowing some applications (P2P applications in particular) 
to behave almost as if they are directly connected to the Internet.  
o
  Address Restricted The NAT forwards incoming connection requests to a 
LAN-side host only when they come from the same IP address with which a 
connection was established. This allows the remote application to send data 
back through a port different from the one used when the outgoing session 
was created.  
o
  Port And Address Restricted The NAT does not forward any incoming 
connection requests with the same port address as an already establish 
connection.