As a network user, you may have often heard mention of terminology such as “network addresses”, “hostnames”, “DNS”, “name-servers”, “registering” your computer, and the like. If you have wondered what all the fuss was about, read below for some answers to your questions.
What is an Internet Name/Address?
Every computer connected to the network has a numeric “address” associated with it, based on its physical location. This number, also known as an “Internet Protocol (IP) address”, is used by network software to route data to the proper destination. Each computer also has a “hostname” associated with it, usually something that is meaningful to humans and indicative of the computer’s organizational relationship within the network.
For example, NACS’ orion UNIX service has a network number of 128.200.80.20, indicating it is located at UCI (128.200) and in Engineering Gateway (subnet 80). The official name of the system is “orion.nacs.uci.edu”, indicating it is associated with the NACS part of UCI. The computer could be moved to a different building with the same name, only the network address would change.
What is the Internet Domain Name Service?
The “Domain Name System” (DNS) is a world-wide distributed database system that maintains network name and address information for every computer connected to the Internet. It is among the most critical components of the network, as virtually nothing works without it. You may not realize it but you are using DNS every time you send an electronic mail message or click on a link in a web page.
How does the Domain Name Service work?
There are thousands of DNS “name-servers” around the world, each one responsible for a portion of the entire Internet “name space”. NACS is responsible for UCI’s portion of the name space, which is known as the “UCI.EDU domain”. In addition to UCI.EDU which provides network address lookups based on hostnames, UCI also manages the “reverse lookup” domain which allows a hostname to be determined from its network address.
When your network software needs to access another system, it first contacts its local name-server. If the desired system is a local UCI host, the name-server supplies the network address directly. If the host is off campus, the name-server contacts the appropriate name-servers in series to determine the network address.
Why register your computer?
It is important that your computer’s name and address be registered in DNS for several reasons. First, it will ensure that you are assigned a unique IP address. Many computer users have encountered problems due to someone else’s computer using their IP address.
Secondly, many information and service providers have restricted their host access to computers which are registered in DNS. There are unscrupulous people who use anonymous, non-registered IP addresses to “attack” hosts and cause various electronic mischief. Lastly, knowing the departmental ownership of systems allows NACS to collect overall statistics concerning network traffic, which is critical for network maintenance and planning.
How can I make sure my host is registered?
If you use NACS computer systems (EA, E4E, Orion, etc.) and are not receiving an error message about your host needing to be registered, your computer is registered. You may also check with your local computing support coordinator, who is likely in charge of registering hosts for your department. If you have further questions, drop NACS a note via our NACS@UCI.EDU e-mail address.