Denial of service attack, Ethernet cabling, Category 5 cable quality – NETGEAR DG834GT User Manual

Page 127

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Reference Manual for the Model DG834GT 108 Mbps Super Wireless ADSL Router

Network and Routing Basics

B-11

August 2004

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

Although Ethernet networks originally used thick or thin coaxial cable, most installations currently
use unshielded twisted pair (UTP) cabling. The UTP cable contains eight conductors, arranged in
four twisted pairs, and terminated with an RJ45 type connector. A normal straight-through UTP
Ethernet cable follows the EIA568B standard wiring as described below in

Table B-1

.

Category 5 Cable Quality

Category 5 distributed cable that meets ANSI/EIA/TIA-568-A building wiring standards can be a
maximum of 328 feet (ft.) or 100 meters (m) in length, divided as follows:

20 ft. (6 m) between the hub and the patch panel (if used)

295 ft. (90 m) from the wiring closet to the wall outlet

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

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