IP address and MAC address concept

[vaibhavjaim]

hi all
Ip address is a unique address....and MAC address is also a unique address...then why we don"t use MAC address instead of Ip address....

waiting 4 reply

[Brar47]

Sorry m not a professional or something but i just started reading his book

So mac address is unique u are right but ip address is not unique

We have many internet providers giving same ip address to a number of users

and secondly i think it is probably more easier to distinguish between location of the hosts and stuff with ip address rather than mac address

i know m not completely right but this is all i can think of

probably someone else will give u a better explanation

[tsunamoro]

Well, my suggestion is to read and understand the "layer model".
Think what happens if you used only the MAC address also as IP address and decided to move an host from a network to another network. How to tell "the system" this? When I say "the system" I mean, for example, routing. IP addressing schema give us the possibility to logically manage a network assigning a logical (ie IP) address that we can change.
Logically manage a network means you are able, for example, to create some kind of hierarchy.

Hope this help.

[eblonk]

Like Tsunamoro said, you can't group (or subnet) MAC addresses. Strictly speaking they are grouped because the first part is exclusive to the manufacturer and thus they are grouped as Cisco, 3Com etc. But that has no practical use in subnetting.
TCP/IP isn't the only system for logical grouping, IPX?SPX and others can do that as well but it is pretty versatile and above all most widely used.

[dbeare]

I agree with what has been posted so far, just wanted to add some thoughts.

The advantage of using an IP scheme and not a MAC scheme for addressing is that it gives the network administrator the flexibility of being able to create addressing and network schemes that fit the organization, rather than being tied down by MAC addresses that are assigned by manufacturers. I can't even begin to imagine how difficult it would be if you had a company with 10,000 employees, hundreds of routers and switches, VLANs and VPNs, and having to manage them all by MAC addresses. IP allows for the network administrator to logically create addressing maps that are easy to understand, change and add to in the future.

Also, managing multicasts, unicasts and broadcasts on a layer 2 basis, which is what MAC addresses are, would be difficult at best and impossible on some levels. This is why we use IP and not MAC for network routing purposes in my opinion.

[pm123]

mac address is unique but is hardware address and the ip address is the logical address or the software address which necessarily not always unique and may be dynamic as in the wireless communications. if u send e-mail to anyone, ip addressing is used because it is the address which the routers recognizes and forwards the packets to and after the static ips have been finalised by the router, then in the local network it searches for the intended machine with the desired mac address or a ARP protocol serves the purpose

[pm123]

on the pages no 95 of the book of todd lamle , there is written:
Yes, I know 0 and 127 are not valid in a Class A network.
Could anyone let me know that why 127 entire network (Class A) is not valid, as only 127.0.0.1 address is the loopback address used and all the other host of 127 network would not be valid? Means {(255*255*255)-1} should be valid hosts with the network 127. But its written that the entire 127 network is not used. Please clear my doubt.

[lildeezul]

becuase the whole 127.0.0.0 /8 network is used for loopback addresing...
On windows machine mainly 127.0.0.1, but they are others out there...

[Fuzz]

on the pages no 95 of the book of todd lamle , there is written:
Yes, I know 0 and 127 are not valid in a Class A network.
Could anyone let me know that why 127 entire network (Class A) is not valid, as only 127.0.0.1 address is the loopback address used and all the other host of 127 network would not be valid? Means {(255*255*255)-1} should be valid hosts with the network 127. But its written that the entire 127 network is not used. Please clear my doubt.

You only need to make one post on the subject, how many different answers are you expecting?

Also, why post it in a thread completely unrelated to your question?

[lildeezul]

You only need to make one post on the subject, how many different answers are you expecting?

Also, why post it in a thread completely unrelated to your question?

Fuzz : you and i think alike my friend. Hahaha :D