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For human consumption, we usually convert the value of each of the bytes to an unsigned decimal value and display them connected by periods to make themeasier to remember. For example, as near as I can tell, as of this writing, the IP address of www.austincc.edu (the college where I teach) is 206.77.150.222 .

Domain Names

What do I mean by www.austincc.edu ?

Even though we can do some tricks to make the numeric IP addresses easier to remember, humans don't do a very good job of remembering long stringsof numbers. Humans remember words and names better. Therefore, most IP addresses have a corresponding name known as a domain name . The domain name for the IP address 206.77.150.222 is www.austincc.edu .

The Domain Name System (DNS) was developed to translate between IP addresses and domain names. Whenever you log your browser onto the internet and attempt to connect to a server using its domain name, the browser firstcommunicates with a DNS server to learn the corresponding numeric IP address. The numeric IP address (and not the domain name) is encapsulated into the data packets and used by the internet protocol to routethose packets from the source to the destination.

(You should also be able to enter 206.77.150.222 into the address field of your browser and access the college where I teach.)

We will learn how to use the Java InetAddress class to find the domain name corresponding to an IP address, and to find the IP address corresponding to a domain name.

What is Your IP Address?

Do you have an IP address and a domain name ?

If (like me) you use a commercial Internet Service Provider (ISP) for your Internet service at home,you probably don't have a fixed IP address or a fixed domain name . Rather, the ISP has a block of IP addresses reserved. When you subscribe to the ISP, the ISP temporarily assigns an IP address to you. That IP address may or may not change over time, but probably will change unless youpay the extra fee for a fixed IP address.

On the other hand, I currently pay for server space from a company in North Carolina under thedomain name www.dickbaldwin.com . My domain has an IP address of 98.129.229.162 . For as long as I continue to pay the bill, that domain name and that IP address will be assigned to me foruse as my personal website.

I suppose that the company could change the IP address at some point provided that they make certain that all of the domain name servers get updatedto reflect the new IP address that corresponds to the domain name.

Ports

Each server computer that you may connect to will be logically organized into ports . These are not physical ports in the sense of the VGA or HDMI port onthe back of your computer. Rather, they are simply logical sub-addresses which you provide to the operating system on the server so that the operating systemcan cause the appropriate server software to "answer the call." We will write a simple server software package that will service several different ports onindependent threads in a future module.

One of the Java books on my bookshelf refers to the IP address as being analogous to the telephone number of a company and the port to be analogous to the employee's telephone extension within that company. (At least that is how telephone systems in companies were organized when I was working in industry.)

Questions & Answers

Do somebody tell me a best nano engineering book for beginners?
s. Reply
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
s.
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Harper
how to fabricate graphene ink ?
SUYASH Reply
for screen printed electrodes ?
SUYASH
What is lattice structure?
s. Reply
of graphene you mean?
Ebrahim
or in general
Ebrahim
in general
s.
Graphene has a hexagonal structure
tahir
On having this app for quite a bit time, Haven't realised there's a chat room in it.
Cied
what is biological synthesis of nanoparticles
Sanket Reply
what's the easiest and fastest way to the synthesize AgNP?
Damian Reply
China
Cied
types of nano material
abeetha Reply
I start with an easy one. carbon nanotubes woven into a long filament like a string
Porter
many many of nanotubes
Porter
what is the k.e before it land
Yasmin
what is the function of carbon nanotubes?
Cesar
I'm interested in nanotube
Uday
what is nanomaterials​ and their applications of sensors.
Ramkumar Reply
what is nano technology
Sravani Reply
what is system testing?
AMJAD
preparation of nanomaterial
Victor Reply
Yes, Nanotechnology has a very fast field of applications and their is always something new to do with it...
Himanshu Reply
good afternoon madam
AMJAD
what is system testing
AMJAD
what is the application of nanotechnology?
Stotaw
In this morden time nanotechnology used in many field . 1-Electronics-manufacturad IC ,RAM,MRAM,solar panel etc 2-Helth and Medical-Nanomedicine,Drug Dilivery for cancer treatment etc 3- Atomobile -MEMS, Coating on car etc. and may other field for details you can check at Google
Azam
anybody can imagine what will be happen after 100 years from now in nano tech world
Prasenjit
after 100 year this will be not nanotechnology maybe this technology name will be change . maybe aftet 100 year . we work on electron lable practically about its properties and behaviour by the different instruments
Azam
name doesn't matter , whatever it will be change... I'm taking about effect on circumstances of the microscopic world
Prasenjit
how hard could it be to apply nanotechnology against viral infections such HIV or Ebola?
Damian
silver nanoparticles could handle the job?
Damian
not now but maybe in future only AgNP maybe any other nanomaterials
Azam
Hello
Uday
I'm interested in Nanotube
Uday
this technology will not going on for the long time , so I'm thinking about femtotechnology 10^-15
Prasenjit
can nanotechnology change the direction of the face of the world
Prasenjit Reply
At high concentrations (>0.01 M), the relation between absorptivity coefficient and absorbance is no longer linear. This is due to the electrostatic interactions between the quantum dots in close proximity. If the concentration of the solution is high, another effect that is seen is the scattering of light from the large number of quantum dots. This assumption only works at low concentrations of the analyte. Presence of stray light.
Ali Reply
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Object-oriented programming (oop) with java. OpenStax CNX. Jun 29, 2016 Download for free at https://legacy.cnx.org/content/col11441/1.201
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