User manual

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Network Terminology
Bridge A bridge is a device that connects two LANs, or two segments of the same LAN that use the
same protocol. Sometimes called “transparent bridges” they work at the OSI model layer 2.
Simply put, they are not concerned with protocols. Their main job is to pass data to a
destination address that is predetermined in the data packet.
With a bridge, all of your computers are on the same network subnet (see Subnet). This means
your computers can communicate with each other an have their own internet connection. If
you assign your own IP addresses be sure to use the same first three (3) octets of the IP
address (for example, 192.168.0.X).
Domain Name Server
(DNS)
A DNS Server is an internet service that translates domain names (for example, in the URL
http//www.telex.com, the domain name is telex.com) into IP addresses. The internet is based
on IP address which are numeric, and since domain names are alphabetic, they are easier to
remember. Every time a domain name is used it must go through the DNS server to be
translated.
Gateway A gateway is a node on a network that serves as an entrance to another network. The gateway
routes traffic from a computer to an outside network that is serving the web pages. For
example, the gateway for a home computer is the ISP provider that connects the user to the
Internet.
In a corporate environment, the gateway often acts as a proxy server and a firewall. Gateways
are similar to routers and switches, in that they forward data to the destination and provide the
path for which the data will travel to the destination.
Hub A hub is a common connection point for devices in a network. A hub has multiple ports.
When a data packet arrives at a hub, it is copied and distributed to all of its ports so that all
nodes on the LAN can see the packets.
There are three types of hubs:
passive hub - this hub serves as a conduit for the data, enabling it to go from one
device to another.
intelligent hub - (also known as manageable hubs) this hub includes additional
features that enable administrators to monitor traffic through the hub.
switching hub - this hub reads the destination address of each packet and then
forwards the data pack to the appropriate port.
IP Address
(Internet Protocol
Address)
An IP Address is an identifier or numerical name for a coputer or device on a network. Data
between computers are routed over the network using these addresses to identify the
computer the message being sent to and the computer the message is being set from.
The format of an IP Address is a 32-bit numeric address wirtten as four numbers separated by
periods. For example, an IP Address looks like 10.100.1.1.
When working within an isolated network (meaning there is no Internet access), IP Addresses
can be assigned at random just as long as they are unique to each computer and device. When
the isolated netwrok is connected to the INternet, registered Internet Addresses must be
obtained. This is to prevent duplication of addresses.
The four numbers in an IP Address are used in different ways to identify a particular network
and host on the network. There are three (3) classes of Internet Addresses:
CLASS A: supports 16 million hosts on each of 127 networks.
CLASS B: supports 65,000 hosts on each of 16,000 networks.
CLASS C: supports 254 hosts on each of 2 million networks.