Netgear WGT624SC WGT624v3 Reference Manual - Page 91

Stateful Packet Inspection, Denial of Service Attack, Ethernet Cabling

Get Netgear WGT624SC - Super G Wireless Router PDF manuals and user guides View all Netgear WGT624SC manuals
Add to My Manuals
Save this manual to your list of manuals

Page 91 highlights

Reference Manual for the 108 Mbps Wireless Firewall Router WGT624 v3 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 straightthrough 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 202-10090-01, April 2005 B-11

  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7
  • 8
  • 9
  • 10
  • 11
  • 12
  • 13
  • 14
  • 15
  • 16
  • 17
  • 18
  • 19
  • 20
  • 21
  • 22
  • 23
  • 24
  • 25
  • 26
  • 27
  • 28
  • 29
  • 30
  • 31
  • 32
  • 33
  • 34
  • 35
  • 36
  • 37
  • 38
  • 39
  • 40
  • 41
  • 42
  • 43
  • 44
  • 45
  • 46
  • 47
  • 48
  • 49
  • 50
  • 51
  • 52
  • 53
  • 54
  • 55
  • 56
  • 57
  • 58
  • 59
  • 60
  • 61
  • 62
  • 63
  • 64
  • 65
  • 66
  • 67
  • 68
  • 69
  • 70
  • 71
  • 72
  • 73
  • 74
  • 75
  • 76
  • 77
  • 78
  • 79
  • 80
  • 81
  • 82
  • 83
  • 84
  • 85
  • 86
  • 87
  • 88
  • 89
  • 90
  • 91
  • 92
  • 93
  • 94
  • 95
  • 96
  • 97
  • 98
  • 99
  • 100
  • 101
  • 102
  • 103
  • 104
  • 105
  • 106
  • 107
  • 108
  • 109
  • 110
  • 111
  • 112
  • 113
  • 114
  • 115
  • 116
  • 117
  • 118
  • 119
  • 120
  • 121
  • 122
  • 123
  • 124
  • 125
  • 126
  • 127
  • 128
  • 129
  • 130
  • 131
  • 132
  • 133
  • 134
  • 135
  • 136
  • 137
  • 138
  • 139
  • 140
  • 141
  • 142
  • 143
  • 144
  • 145
  • 146
  • 147
  • 148
Reference Manual for the 108 Mbps Wireless Firewall Router WGT624 v3
Network, Routing, Firewall, and Basics
B-11
202-10090-01, April 2005
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