NETGEAR WGT624 manual Ethernet Cabling, Stateful Packet Inspection

Reference Manual for the 108 Mbps Wireless Firewall Router WGT624

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.

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
Network, Routing, Firewall, and Basics				B-11

M-10153-01