Netgear Router WGR614 User Manual

Reference Manual for Cable/DSL Wireless Router WGR614 
Network, Routing, Firewall, and Basics B-5
 
As a shorter alternative to dotted-decimal notation, the netmask may also be expressed in terms of 
the number of ones from the left. This number is appended to the IP address, following a backward 
slash (/), as “/n.” In the example, the address could be written as 192.168.170.237/24, indicating 
that the netmask is 24 ones followed by 8 zeros. 
Subnet Addressing
By looking at the addressing structures,...

Reference Manual for Cable/DSL Wireless Router WGR614 
B-6 Network, Routing, Firewall, and Basics
 
Although the preceding example uses the entire third octet for a subnet address, note that you are 
not restricted to octet boundaries in subnetting. To create more network numbers, you need only 
shift some bits from the host address to the network address. For instance, to partition a Class C 
network number (192.68.135.0) into two, you shift one bit from the host address to the network 
address. The new...

Reference Manual for Cable/DSL Wireless Router WGR614 
Network, Routing, Firewall, and Basics B-7
 
Configure all hosts on a LAN segment to use the same netmask for the following reasons:
• So that hosts recognize local IP broadcast packets
When a device broadcasts to its segment neighbors, it uses a destination address of the local 
network address with all ones for the host address. In order for this scheme to work, all devices 
on the segment must agree on which bits comprise the host address. 
• So...

Reference Manual for Cable/DSL Wireless Router WGR614 
B-8 Network, Routing, Firewall, and Basics
 
Single IP Address Operation Using NAT
In the past, if multiple PCs on a LAN needed to access the Internet simultaneously, you had to 
obtain a range of IP addresses from the ISP. This type of Internet account is more costly than a 
single-address account typically used by a single user with a modem, rather than a router. The 
WGR614 router employs an address-sharing method called Network Address...

Reference Manual for Cable/DSL Wireless Router WGR614 
Network, Routing, Firewall, and Basics B-9
 
This scheme offers the additional benefit of firewall-like protection because the internal LAN 
addresses are not available to the Internet through the translated connection. All incoming 
inquiries are filtered out by the router. This filtering can prevent intruders from probing your 
system. However, using port forwarding, you can allow one PC (for example, a Web server) on 
your local network to be...

Reference Manual for Cable/DSL Wireless Router WGR614 
B-10 Network, Routing, Firewall, and Basics
 
Domain Name Server
Many of the resources on the Internet can be addressed by simple descriptive names such as 
www.NETGEAR.com. This addressing is very helpful at the application level, but the descriptive 
name must be translated to an IP address in order for a user to actually contact the resource. Just as 
a telephone directory maps names to phone numbers, or as an ARP table maps IP addresses to 
MAC...

Reference Manual for Cable/DSL Wireless Router WGR614 
Network, Routing, Firewall, and Basics B-11
 
What is a Firewall?
A firewall is a device that protects one network from another, while allowing communication 
between the two. A firewall incorporates the functions of the NAT router, while adding features for 
dealing with a hacker intrusion or attack. Several known types of intrusion or attack can be 
recognized when they occur. When an incident is detected, the firewall can log details of the...

Reference Manual for Cable/DSL Wireless Router WGR614 
B-12 Network, Routing, Firewall, and Basics
 
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 and pinout as described in 
Ta b l e 7-1....

Reference Manual for Cable/DSL Wireless Router WGR614 
Network, Routing, Firewall, and Basics B-13
 
The WGR614 router incorporates Auto UplinkTM technology (also called MDI/MDIX). Each 
LOCAL Ethernet port will automatically sense whether the Ethernet cable plugged into the port 
should have a normal connection (e.g. connecting to a PC) or an uplink connection (e.g. 
connecting to a router, switch, or hub). That port will then configure itself to the correct 
configuration. This feature also eliminates...

Reference Manual for Cable/DSL Wireless Router WGR614 
B-14 Network, Routing, Firewall, and Basics