User manual NETGEAR WGM124

[. . . ] 4500 Great America Parkway Santa Clara, CA 95054 USA Version 1. 0 December 2004 December 2004 © 2004 by NETGEAR, Inc. Microsoft, Windows, and Windows NT are registered trademarks of Microsoft Corporation. Other brand and product names are registered trademarks or trademarks of their respective holders. Statement of Conditions In the interest of improving internal design, operational function, and/or reliability, NETGEAR reserves the right to make changes to the products described in this document without notice. NETGEAR does not assume any liability that may occur due to the use or application of the product(s) or circuit layout(s) described herein. Federal Communications Commission (FCC) Compliance Notice: Radio Frequency Notice This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to part 15 of the FCC Rules. [. . . ] When an incident is detected, the firewall can log details of the attempt, and can optionally send E-mail to an administrator notifying them of the incident. Using information from the log, the administrator can take action with the ISP of the hacker. In some types of intrusions, the firewall can fend off the hacker by discarding all further packets from the hacker's IP address for a period of time. B-10 December 2004 Network, Routing, and Firewall Basics NETGEAR Wireless Router Setup Manual 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 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. Network, Routing, and Firewall Basics December 2004 B-11 NETGEAR Wireless Router Setup Manual Table B-1. Pin 1 2 3 4 5 6 7 8 UTP Ethernet cable wiring, straight-through Signal Transmit (Tx) + Transmit (Tx) Receive (Rx) + Wire color Orange/White Orange Green/White Blue Blue/White Green Brown/White Brown Receive (Rx) - 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. (3 m) from the wall outlet to the desktop device The patch panel and other connecting hardware must meet the requirements for 100 Mbps operation (Category 5). Only 0. 5 inch (1. 5 cm) of untwist in the wire pair is allowed at any termination point. A twisted pair Ethernet network operating at 10 Mbits/second (10BASE-T) will often tolerate low quality cables, but at 100 Mbits/second (10BASE-Tx) the cable must be rated as Category 5, or Cat 5, by the Electronic Industry Association (EIA). A Category 5 cable will meet specified requirements regarding loss and crosstalk. In addition, there are restrictions on maximum cable length for both 10 and 100 Mbits/second networks. B-12 December 2004 Network, Routing, and Firewall Basics NETGEAR Wireless Router Setup Manual Inside Twisted Pair Cables For two devices to communicate, the transmitter of each device must be connected to the receiver of the other device. The crossover function is usually implemented internally as part of the circuitry in the device. Computers and workstation adapter cards are usually media-dependent interface ports, called MDI or uplink ports. Most repeaters and switch ports are configured as media-dependent interfaces with built-in crossover ports, called MDI-X or normal ports. Auto Uplink technology automatically senses which connection, MDI or MDI-X, is needed and makes the right connection. Figure B-4 illustrates straight-through twisted pair cable. Figure B-4: Straight-Through Twisted-Pair Cable Figure B-5 illustrates crossover twisted pair cable. Figure B-5: Crossover Twisted-Pair Cable Network, Routing, and Firewall Basics December 2004 B-13 NETGEAR Wireless Router Setup Manual Figure B-6: Category 5 UTP Cable with Male RJ-45 Plug at Each End Note: Flat "silver satin" telephone cable may have the same RJ-45 plug. [. . . ] PPP over ATM is a protocol for connecting remote hosts to the Internet over an always-on connection by simulating a dial-up connection. PPPoE PPPoE. PPP over Ethernet is a protocol for connecting remote hosts to the Internet over an always-on connection by simulating a dial-up connection. PPP over ATM PPPoA. PPP over ATM is a protocol for connecting remote hosts to the Internet over an always-on connection by simulating a dial-up connection. PPTP Point-to-Point Tunneling Protocol. A method for establishing a virtual private network (VPN) by embedding Microsoft's network protocol into Internet packets. router A device that forwards data between networks. [. . . ]