What's the difference between a Mac Address and an IP Address?

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It's funny you use a postal metaphor here. My father once asked me how his computer "knows" how to talk to a computer across the country. I used a postal metaphor to describe how Internet traffic is routed.

When you mail a letter, how does the letter "know" how to get across the country? It doesn't have to. The postman who picks up the mail only has to know how to get it from your mailbox to the local post office. Someone at the local post office only has to know that a letter going to Florida gets sent to the White Plains post office. From there, someone only has to know that it goes to the New York City branch. From there, someone sends it on a truck to Miami. From there, it's put on a truck to the local post office. And from there, it's put on a truck to be delivered.

At each step, all that's needed to be known is which direction to send it on its next step along the way.

Leo - one part of the original question asks about the difference between IP addresses you get 'for free' and those you buy. I think this is asking about the difference between a dynamic and a static IP address - most ISPs will give you a dynamic IP address as standard but will charge you for a fixed IP address; a dynamic IP address is fine if you just use email and the internet, but if, for example, you want to run your own web server, and host it yourself on your own computer, you need a static IP address.

It gives a good picture about the IP and MAC addresses.
Does the MAC address also go along with the IP address as hidden-part of the Header Details of the Email to the receiving PC / Server ?

IP and MAC - Very nicely differentiated.
I have some doubts. Will the MAC address also go with the IP address as part of the Header details along with the Mail exchange ? Can the Mail be tracked back to the MAC no (ie., the Mail originating PC )?
What is the real purpose MAC Address ?

Dear Sir Leo:

Hope you will fine and healthy. I'm so happy from your site and your information to take us and u solve our problems.
Sir i have Three quetions.
1. what is diffrent between Table and Query in Access programm?

2. What is different between routing protocols and routed protocols?

3. What is different between ISA server and Proxy server?

Very interesting in fact I understood your metaphor. Perhaps you can answer a question.
I'm installing a new machine, I'm connected to the internet but cannot open my browser (page cannot be displayed). Checking my IP address it appears as all letters.

Any help will be greatly appreciated

Would love to know the answer to this above post as well.

IP and MAC - Very nicely differentiated.
I have some doubts. Will the MAC address also go with the IP address as part of the Header details along with the Mail exchange ? Can the Mail be tracked back to the MAC no (ie., the Mail originating PC )?
What is the real purpose MAC Address ?

Why would someone want the same mac address as me? I just found out through my Internet provider that some one else had the same mac address as me, which is why my internet wasn't working. How does that happen, and should I be concerned?

Dear Sir,

This is indeed a useful site.

Please advise me the followings:
Is it mandantory to get a MAC address (OUI/IAB),
even if, I used the ethernet device on a LAN only?

Thank you.

Regards,
Octavius

Dear Leo
Can you connect Macs and PC's to the same server?
How?
Thanks,Jetrue

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