Need of IP address and Port

Question

1.00/5 (1 vote)

See more:

I have some set of queries.

1. Why do we have IP address and port number when one would suffice to identify
the destined target?

2. I am running a process as user1. Will I be allowed to bind to a port
number 980 as part of this process execution?

3. Which of the network delay components are controllable at our end?

4. My admin set my PC which is in a LAN with an IP address 10.3.4.5
Suddenly, when I rebooted my PC it threw an error dialog
'IP conflict'. how the PC was able to detect the IP conflict?

5. I was remote logged in to a web server to check system status from my PC via
putty tool. Everything was ok in the web server as seen in the system logs.
Then I took a quick 2 minute break for coffee, when I came back,
I saw an error dialog on my PC which read 'Server unexpectedly close the
connection'. Can you tell me what could have happened with network protocol level
details?

Please help,
Thanks in advance

Posted 29-Nov-13 17:55pm

srmohanr

Updated 29-Nov-13 18:01pm

v3

Add a Solution

4 solutions

Solution 2

Hi
An Internet Protocol address (IP address) is a numerical label assigned to each device from computer network same as 127.0.0.1 each part of this number are between 0-255(0-255.0-255.0-255.0-255) after identify target machine with IP Address from computer network ( assume you want find a home from city with post address) you should use the port, The location where data is exchanged is called a port ( in the city example after identify home you should use port same as door or window to the incoming at home ;-) ) Thus the IP address is enough to get the data to the right computer but does not say which application should receive the data on that machine. That is what the port number does. For example, by convention anything sent to TCP port 80 will be forwarded to a web server running on that machine.

for getting more information please follow of these links:

http://en.wikipedia.org/wiki/IP_address[^]
http://whatismyipaddress.com/ip-address[^]

Best Regards.

Posted 29-Nov-13 18:08pm

Aydin Homay

Updated 29-Nov-13 18:09pm

v2

Comments

Sergey Alexandrovich Kryukov 30-Nov-13 0:33am

Correct, a 5.
—SA

Aydin Homay 30-Nov-13 2:49am

Thank you

Sergey Alexandrovich Kryukov 30-Nov-13 18:43pm

Thank you, Aydin.
—SA

Solution 3

The short answer is: because this is designed this way. A bit more serious: your "one would suffice" is nothing but your fantasy, related to lack of understanding how IP works. Your whole approach is wrong: you should first learn the basics of IP addressing (as the minimum) and only then do some conclusions and try to make statements.

Now, let's think: an IP address is a limited resource, because this is something unique, either world-unique, or unique to some network. Even though this is not a problem to have several IP address per computer, usually it has one or two, hardly more. And a single host, especially used as a server, usually executes several different services. Yes, on the same IP address. Hence, the port numbers. Another thing is this: IP address identifies the host, while port number identifies the "type of the service" and is associated with certain protocol. Even though different port numbers can be used with the same protocol (thus allowing to execute more then one service accessible via the same protocol, which is an important feature of IP addressing), standard protocol have standard associated default port numbers meeting the world-wide standard supported by IANA authority. By the way, any decisions related to port number should be made based on consulting this standard document: http://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml[^].

—SA

Posted 29-Nov-13 18:15pm

Sergey Alexandrovich Kryukov

Comments

Ron Beyer 30-Nov-13 0:22am

+5, a basic understanding of IP layer and how DHCP works can answer a lot of the questions.

Sergey Alexandrovich Kryukov 30-Nov-13 0:31am

Thank you, Ron.
—SA

Aydin Homay 30-Nov-13 2:50am

+5

Sergey Alexandrovich Kryukov 30-Nov-13 18:46pm

Thank you, Aydin.
—SA

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Homero Rivera · Accepted Answer · 2013-11-29T18:01:00

Solution 1

The IP Address works as the computer's name in the network, while the port number is good to identify what application in that computer needs the data.

All data coming from another computer will be requested by an application, but which?
We have HTTP applications (web browsers), MS SQL Server, E-mail (SMTP, others), Messengers, videogames, etc...

So how do we direct the data from the network to the right application?
With the use of a port number.

Posted 29-Nov-13 18:01pm

Homero Rivera

Comments

srmohanr 30-Nov-13 0:05am

Thanks for you help.

Homero Rivera 30-Nov-13 0:11am

Welcome! additionally, read http://en.wikipedia.org/wiki/List_of_port_numbers notice port 80 for HTTP, 443 for HTTPS, 666 for Doom videogame and 20 for FTP.

srmohanr 30-Nov-13 0:12am

Can u pls help me clarify rest of my questions..

Homero Rivera 30-Nov-13 0:17am

Are these miscellaneous networking/connectivity problems? It seems to me after reading you have a problem with an app, then another one, etc... Question 2, what application/process were you running?
Question 5, a web server application may shut you down after 2 minutes if it detects no activity.

srmohanr · Accepted Answer · 2013-11-29T19:04:00

Question 4:

VB

If your computer has DHCP enabled, often rebooting the computer allowing it to get a new address assigned to it will resolve the issue.

When you are not sure if you are using DHCP or are using a static IP address, either try to locate the computer or device using the IP address or manually change your IP address to something else.  For example, if the address was 192.168.1.105 changing it to 192.168.1.112.

Question 5:

VB

In the remote server machine, they will set the property "Set Time Limit for Idle Remote Desktop Services Sessions".  Once the idle time breaches it limit, it automatically close the connection from remote desktop and it shows the message "Server unexpectedly close the connection"