Netgear WGT634U 참조 매뉴얼

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Reference Manual for the 108 Mbps Wireless Media Router WGT634U
Network, Routing, Firewall, and Basics
B-11
April 2004, 202-10018-02
Stateful Packet Inspection
Unlike simple Internet sharing routers, a firewall uses a process called stateful packet inspection to 
ensure secure firewall filtering to protect your network from attacks and intrusions. Since 
user-level applications such as FTP and Web browsers can create complex patterns of network 
traffic, it is necessary for the firewall to analyze groups of network connection states. Using 
Stateful Packet Inspection, an incoming packet is intercepted at the network layer and then 
analyzed for state-related information associated with all network connections. A central cache 
within the firewall keeps track of the state information associated with all network connections. 
All traffic passing through the firewall is analyzed against the state of these connections in order to 
determine whether or not it will be allowed to pass through or rejected.
Denial of Service Attack
A hacker may be able to prevent your network from operating or communicating by launching a 
Denial of Service (DoS) attack. The method used for such an attack can be as simple as merely 
flooding your site with more requests than it can handle. A more sophisticated attack may attempt 
to exploit some weakness in the operating system used by your router or gateway. Some operating 
systems can be disrupted by simply sending a packet with incorrect length information.
Ethernet Cabling
Most Ethernet networks now use unshielded twisted pair (UTP) cabling. UTP cable has eight 
wires arranged in four twisted pairs, and terminated with an RJ45 connector. Normal straight- 
through UTP Ethernet cable follows the EIA568B standard as described in 
Table B-1.
UTP Ethernet cable wiring, straight-through
Pin
Wire color
Signal
1
Orange/White
Transmit (Tx) +
2
Orange
Transmit (Tx) -
3
Green/White
Receive (Rx) +
4
Blue
5
Blue/White
6
Green
Receive (Rx) -
7
Brown/White
8
Brown