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Question: What is an IP Address?

Answer: An IP Address is a "computers" return address. This return address is needed so the information you request will make it back to your computer.

Your IP (Internet Protocol) Address is a unique set of four numbers (0-255) that is always in the form of 255.255.255.255. Each computer hooked up to the internet has to have these numbers so that the requested information has a place to be delivered.

Some computers have a FIXED (static) number - in other words - ever time you turn on the computer you have the same numbers.

Other computers allow the network server to assign their network configuration from a DHCP (Dynamic Host Configuration Protocol) Server automatically. Instead of manually assigning IP numbers DHCP draws from a list of addresses and assigns them as needed. Ideally a DHCP server meets the highest load most of the time. For example a university dorm may have 500 internet connections but the normal maximum load is 170 concurrent users. A DHCP server could manage this and save resources for the university by not having to purchase right to all 500 IP addresses. This also reduces the likelihood of configuration errors for the users - assuring that no two IP numbers are the same.

Your Internet Service Provider (ISP) probably has your IP Address associated to a Domain Name also. The Domain Name is not the IP Address but they are related. Take a look at the following information.

Now you see why they have both - the number for the computers and the name for us. (It is easier for us to remember.)

Your networks numbers are assigned by your Internet Service Providers (ISP) under authority of the Internet Assigned Numbers Authority (IANA) who in turn gets the numbering scheme from InterNic. (NO, you don't need to remember any of that.)

There is a lot of information that you are sending out with your requests. There has to be enough information for the server to know where to return your requests and there is also enough information for someone to find out exactly where your machine is located geographically. I'm not telling you to scare you - but so that you are aware.

There are four different 32 bit address formats for a network depending on the size.

Class A addresses are for a large network
1 bit as 0 - 7 bits network - 24 bits local = 1 + 7 + 24 = 32
Network.local.local.local
Class B addresses are for a medium network
2 bits as 10 - 14 bit network - 16 bits local = 2 + 14 + 16 = 32
Network.network.local.local
Class C addresses are for smaller networks
3 bits as 110 - 21 bits network - 8 bits local = 3 + 21 + 8 = 32
Network.network.network.local
Class D addresses are for Multicast addresses
4 bits as 1110 - 28 bits Multicasting = 4 + 28 = 32
Multicasting is basically sending a single copy of something to multiple computers - reducing bandwidth

(i.e. a classroom where a movie should be sent to all 50 computers)
Multicasting IP addresses are currently in the range of 224.0.0.0 through 239.255.255.255

IP Addresses are sometimes referred to as dot addresses. The computer actually reads these as a set of 4 hexadecimal numbers (0-F). Since we live in a base 10 world, we convert these hexadecimal numbers to decimals and separating them by dots (.) helps us identify the 4 numbers. Without the dots it's hard to know if 1922435242 is 192.24.35.242 or 192.243.5.242 or even some other combination.

Hexadecimal- C0 F3 05 52 base 10- 192 243 5 242 dot address- 192.243.5.242

Question: What if I don't want to send out my IP Address?

Answer: Don't use the internet. Really, there is no way to get information back without the IP Address being sent out. Some sites have been set up as a retrieving station but your IP Address has to be sent there so it's really kind-of pointless. If you use the internet your IP Address is public information. The header of your e-mail also contains the IP Address of the computer that sent the document.

Answer: A firewall acts as a screening device for all of your requests. If you request a web page, the request is sent from your computer to the server through the firewall. The IP Address that the server sees requesting the document is your firewall - the server sends the information to the firewall and the firewall forwards the information to you. Under these circumstances, your IP Address is not seen by the server. (But your system administrator could help locate where the information was sent if necessary.)

Answer: By tracing the route to the IP Address that the data is being transferred, you can pinpoint the location of that IP Address. Below is a sample I ran from an e-mail I received.

1	c7500.usd.edu	(192.55.228.252 ):	146ms	156ms	139ms
2	c7000.usd.edu	(192.55.228.243 ):	144ms	141ms	150ms
3	sd-sf-hub-s1.sd.net	(198.180.188.129):	137ms	154ms	138ms
4	sxf0-s46.cp.verio.net	(199.240.75.81 ):	159ms	129ms	133ms
5	oma1-h010.cp.verio.net	(128.242.8.113 ):	198ms	173ms	280ms
6	oma0-fa000.cp.verio.net	(128.242.8.81 ):	184ms	179ms	171ms
7	lnk-s000.cp.verio.net	(128.242.8.70 ):	176ms	176ms	178ms
8	sl-gw4-kc-10-0.sprintlink.net	(144.232.131.1 ):	255ms	228ms	219ms
9	sl-bb11-kc-0-3.sprintlink.net	(144.232.2.57 ):	241ms	214ms	196ms
10	sl-bb11-fw-3-1.sprintlink.net	(144.232.8.77 ):	204ms	*	274ms
11	sl-bb11-fw-8-0.sprintlink.net	(144.232.11.5 ):	194ms	189ms	197ms
12	sl-bb10-sea-0-0.sprintlink.net	(144.232.8.54 ):	290ms	278ms	300ms
13	sl-gw3-sea-0-0-0.sprintlink.net	(144.232.6.42 ):	321ms	260ms	247ms
14	sl-nwnet-1-0-1.sprintlink.net	(144.228.96.26 ):	252ms	294ms	258ms
15	uwbr1-fe4-0-0.cac.washington.edu	(198.32.170.12 ):	282ms	282ms	237ms
16	iron-v50.cac.washington.edu	(140.142.155.68 ):	267ms	246ms	270ms
17	jason03.u.washington.edu	(140.142.77.10 ):	264ms	268ms	286ms

A call to the University of Washington could actually pinpoint the room where this machine was physically located. and you can even throw a map up on the screen with the beginning and destination points.



and can even put up the following information

Host Name	jason03.u.washington.edu
IP Address	140.142.77.10
Response Time	284(ms)
Location	United States:Washington:Seattle
Lat/Long	47.61/-122.33

Question: Where can I look to find out the general location of an IP address?

Answer: NetGeo provides a web based interface to get the general information for an IP address. It searches its database for the IP address - which may or may not have the IP address that you are inquiring about.

Another one - ARIN's Whois.

235890

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