GeekInterview.com
Series: Subject: Topic:
Question: 72 of 110

Why do we need IP address when the MAC address is unique? Can't we communicate only with MAC address?

Asked by: Interview Candidate | Asked on: Apr 4th, 2007
Showing Answers 1 - 18 of 18 Answers
koolyan

Answered On : Apr 16th, 2007

View all answers by koolyan

MAC address is the basis on which communication occurs.However we need IP  address to be able to create a routing table ,that enables faster  commnication.Lots of communication algorithms take use of IP address ( Network address +SubNet masks) to be able to route packages faster.

Yes  1 User has rated as useful.
  
Login to rate this answer.
danish

Answered On : Sep 19th, 2007

We need I.P address because when we work on LAN we can communicate without I.P address with the help of NETBIOS and WINS but inWAN we work on network layer anddata frame becomes packet and packet need I.P address for routing

  
Login to rate this answer.

The actual answer is:-

Ip address(network address) is just use for transfering informatiom from one network to an other.travelling of information among networks uses ip addresses.

Mac addresses(physical addresses) is actually uses for distrubution of information.so, the summay is:-

1) carring of information from one network to another.
2) distrubtion of information(resources) is based upon mac address.

example:-
Network A , Network B and Network C are three networks.all network are having 5 nodes(client).if i want to send information to node 3 for network B.

Solution:-
1) first i send infomation to network by the help of IP address of that network(Network B).Ip addresses are unique on network layer(this is the fact).  

2)after that i will send infomation to node 3 of network B by the help of mac address which is unique at layer 2(DLL).

Yes  1 User has rated as useful.
  
Login to rate this answer.
rama1972

Answered On : May 20th, 2008

View all answers by rama1972

IP address (network address) is just used for transferring information from one network to another network. Travelling of information among networks uses IP addresses. It is used to identity the network and host.

A MAC address (physical addresses) is used for distribution of information with in the network segment. The Ethernet uses MAC address to transfer data between hosts. When its used with IP network, the IP address is resolved using ARP protocol to find the MAC address of the end device and the data is transmitted.

Port numbers are used by the TCP/UDP protocol to isolate the traffic which is multiplexed and sent by the user application. For example, the user device, can open multiple applications at the same time like, multiple web browsers, email and FTP. To identify the data individually the port number are used.

  
Login to rate this answer.
hellohaneef

Answered On : Jul 26th, 2008

View all answers by hellohaneef

I agree with you that is MAC address is unique but for we cant remember MAC address for communication and also MAC address cant define which network you belongs to.

Yes  1 User has rated as useful.
  
Login to rate this answer.
niky_008

Answered On : Jan 30th, 2009

View all answers by niky_008

We need IP address becoz it shows System IP but Mac address shows identity of the device e.g. LAN card

  
Login to rate this answer.
shandhiya

Answered On : Jul 24th, 2009

View all answers by shandhiya

IP address is used to identify uniquely the device.

MAC is used to identify the node and to find the next hop address.

  
Login to rate this answer.
sitanshuray

Answered On : Jun 17th, 2010

View all answers by sitanshuray

The answer is that the IP Address is at the "Software or Logical level, and helps to establish communication between 2 or more Networks at the OSI (Network Level), whereas the MAC Address is at the OSI (Data Link Layer), which has the Physical Address of the actual node (machine). Final Data Distribution (Information Transfer) from the Network Segments (originally PAckets at the Transport Layer) to the Destination Client Node must work at he PHYSICAL LEVEL which starts at the DATA LINK LAYER.

The final Layer in the OSI model (Physical Layer) then translates the MAC ADDRESS to the actual WIRES (RJ45) etc. which work at the ELECTRONS LEVELS.

ONLY MAC ADDRESSES and NO IP ADDRESS will not work. Software at the TRANSPORT LAYER (TCP and IP) does not support physical addresses.

  
Login to rate this answer.
Surajit Biswas

Answered On : Aug 24th, 2010

View all answers by Surajit Biswas

For layer2 of networking, i.e. the Media Access Control layer, Ethernet address or MAC address is unique.


For layer3 of networking, i.e. the Network Layer, IP address is unique.

For a network segment, e.g. LAN , we can communicate with help of NETBIOS and WINS.
But we need IP address for WAN. In WAN we see different requirement like to follow ROUTING ALGORITHM , SUBNET MASK etc......these are impossible by MAC addresss.

  
Login to rate this answer.
Syed Zeeshan

Answered On : Nov 16th, 2011

Ip address is just used for transferring information from one Network to another Network.It will just transfer the information from one network to another.

Whereas,the Mac Address is actually responsible for distributing that information to actual Host in the Network.

  
Login to rate this answer.
gaurav

Answered On : Nov 18th, 2011

the function of mac address and ip address different mac address is physical address which is not work on Internet. but ip address is used to communicate with in world. no we cannot communicate only with mac address because this is physical address and communication possible on logical address.

  
Login to rate this answer.
prashant

Answered On : Mar 4th, 2012

the answer would be our ip address determines our location........if we use a mac instead then we have to search the whole internet to forward a packet, this would flood the network. The advantage of ip is that it is divided on region basis and to forward a packet we have a path to follow

IP address is a logical arrangement whereas a mac is not a logical arrangement.......its random

it is easy to trace down a station with an ip coz its divided according to region whereas in mac it is not possible.

  
Login to rate this answer.
Ibrahim Kay

Answered On : Jun 8th, 2012

Consider this: What if there was no IPs? Can every computer in the world ARP every other computer in the world? Can indefinite numbers of switches be connected/trunked together between New York, California, and Burma too? Say you did this smartly, with a hub-spoke topology, how many MAC entries would the ports on those central switches actually have? MAC addresses are quite random, each switch would have to memorize every single last MAC of every device reachable on every port on a global scale in order for packet switching to operate..

UNLESSSSSSS, you developed a way to logically assign MAC addresses, where your MAC would fall into a subnet and your LAN would all share the same MAC address beginning but have logically assigned bits at the end, that way switches don't need EVERY MAC, they just need your network MAC and then your local switch handles the rest.

That would do fine, and that right there is precisely what IP addresses do.

Only problem is, if you don't have a physical address hard-coded, then how can the machine ever use DHCP?

Your next question might be, yeah but isn't the 48-bit MAC address a little more scalable than the 32-bit IP add?

Sure but that's why they are working on IPv6, which is more scalable than even that.

I feel that this is what you meant in your question, I hope that helped.

  
Login to rate this answer.
mrsamba

Answered On : Jun 26th, 2012

View all answers by mrsamba

IP address is used identified the nodes on the networks

  
Login to rate this answer.
Emre Yilmaz

Answered On : Sep 18th, 2012

Ibrahim Kay has a good approach for the solution but there is a missing thing. If we could see the future in those days or had required things like high bandwidth and lots of equipment that connected to internet at that time maybe vendors could build special MAC for this problem.

Some bits of it maybe expresses states or some regions. Furthermore Ethernet is not only one layer 2 protocol.. there is also Frame Relay, ATM etc. For example think of vpi/vci logic, why do we represent vpi with only 8/12 bits or 16 bits for vci?

Couldnt be much more? What is the behind of that logic?

Because all of the requirements is enough at that time. On the other hand different communities develop different technologies such as Ethernet, ATM, Frame/Relay, etc. But all of them are solutions for local area network and it is enough in those days. Then networking burst, spread to wide areas and people need much more end points and also they need to integrates different technologies into one logical network layer which is called Network layer or OSI layer 3 now.

  
Login to rate this answer.
Nahshon

Answered On : Sep 26th, 2012

Mac address are layer 2, while IP address is layer 3 that is required for TCP/IP to work, which is the basis on data traffic.

  
Login to rate this answer.
Rahul

Answered On : Dec 22nd, 2012

Technology has divided into two part Hardware part and Software part,
e.g
When we insert the LAN card or NIC card into computer,our hardware part is ready,when we installed driver to it our software part is ready,but for proper communication there must be binding between IP Address and MAC Address this binding is stored in ARP table,technology uses a mac address FOR COMMUNICATION Upper layer uses a IP Address.

  
Login to rate this answer.
nathsambu

Answered On : Dec 22nd, 2012

View all answers by nathsambu

MAC address is the physical address of computer. It can not change. But Ip address can change if we want.
By using ip address , we can ping from more than one computer to one computer and get reply.
Example: first pc ip 192.168.1.1
second pc ip 192.168.1.2
Third pc ip 192.168.1.3

If we ping from 192.168.1.1 & from 192.168.1.2 to 192.168.1.3 at a time, 192.168.1.3 able to give reply to both 192.168.1.1 & 192.168.1.2

This is not possible in case of Only MAC address

  
Login to rate this answer.

Give your answer:

If you think the above answer is not correct, Please select a reason and add your answer below.

Related Open Questions

Ads

Connect

twitter fb Linkedin GPlus RSS

Ads

Question Categories

Bluetooth Interview Questions

Client Server Interview Questions

Computer Networks Interview Questions

Networks and Security Interview Questions

Interview Question

 Ask Interview Question?

 

Latest Questions

Interview & Career Tips

Get invaluable Interview and Career Tips delivered directly to your inbox. Get your news alert set up today, Once you confirm your Email subscription, you will be able to download Job Inteview Questions Ebook . Please contact me if you there is any issue with the download.