IP address

kirthika · 08-02-2011, 08:51 AM

Does the computer with same wi-fi connection have same IP address?

TobiSGD · 08-02-2011, 09:04 AM

No, every computer (or other network device) has to have a unique IP within your network.

onebuck · 08-02-2011, 09:18 AM

Hi,

Welcome to LQ!

Quote:

Originally Posted by kirthika

Does the computer with same wi-fi connection have same IP address?

Linux Home Networking: Ch02 Introduction to Networking should help you to understand things.

Rute Tutorial & Exposition: 25. Introduction to IP should expand things a bit;

Quote:

excerpt from '25.4 Computers on a LAN';
LANs work as follows. Network cards transmit a frame to the LAN, and other network cards read that frame from the LAN. If any one network card transmits a frame, then all other network cards can see that frame. If a card starts to transmit a frame while another card is in the process of transmitting a frame, then a clash is said to have occurred, and the card waits a random amount of time and then tries again. Each network card has a physical address of 48 bits called the hardware address (which is inserted at the time of its manufacture and has nothing to do with IP addresses). Each frame has a destination address in its header that tells what network card it is destined for, so that network cards ignore frames that are not addressed to them.
Since frame transmission is governed by the network cards, the destination hardware address must be determined from the destination IP address before a packet is sent to a particular machine. This is done is through the Address Resolution Protocol (ARP). A machine will transmit a special packet that asks ``What hardware address is this IP address?'' The guilty machine then responds, and the transmitting machine stores the result for future reference. Of course, if you suddenly switch network cards, then other machines on the LAN will have the wrong information, so ARP has time-outs and re-requests built into the protocol. Try typing the command arp to get a list of hardware address to IP mappings.

Just a few links to aid you to gaining some understanding;

  1 Linux Documentation Project 
2 Rute Tutorial & Exposition 
3 Linux Command Guide  
4 Bash Beginners Guide 
5 Bash Reference Manual 
6 Advanced Bash-Scripting Guide 
7 Linux Newbie Admin Guide 
8 LinuxSelfHelp 
9 Utimate Linux Newbie Guide
10 Linux Home Networking
11 Virtualization- Top 10

The above links and others can be found at 'Slackware-Links'. More than just Slackware® links!

kirthika · 08-02-2011, 09:20 AM

In "www.whatismyip.com" website it shows us our current IP address. I am using my laptop in a LAN connecion(college wi-fi connection). It shows my IP address. My friend near me gets the same IP address. How is it possible?

corp769 · 08-02-2011, 09:21 AM

To add what Gary said.... A physical connection and a wireless connection use two completely different network cards. Each card has a unique MAC address assigned to it from the factory, so each device will be given a different IP address from your router. That pretty much sums that up for you; Please read the links given to you though, as they will definitely help you understand networking in depth.

Cheers,

Josh

corp769 · 08-02-2011, 09:24 AM

Quote:

Originally Posted by kirthika

In "www.whatismyip.com" website it shows us our current IP address. I am using my laptop in a LAN connecion(college wi-fi connection). It shows my IP address. My friend near me gets the same IP address. How is it possible?

That is because the external IP address of your network's router is the same. You two will have different LAN IP addresses. On the command line, type the following:

Code:

ifconfig

Have your friend do the same, and you will notice that the actual IP address of your interface will be different from his. On my network, my LAN IP address is 192.168.2.91, whereas my external IP address is the actual route to the external WAN, or internet.

ibaydan · 08-02-2011, 09:34 AM

Quote:

Originally Posted by corp769

That is because the external IP address of your network's router is the same. You two will have different LAN IP addresses. On the command line, type the following:

Code:

ifconfig

Have your friend do the same, and you will notice that the actual IP address of your interface will be different from his. On my network, my LAN IP address is 192.168.2.91, whereas my external IP address is the actual route to the external WAN, or internet.

thats true

corp769 · 08-02-2011, 09:45 AM

Quote:

Originally Posted by ibaydan

thats true

I know it's true

Any other questions?