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needed ur attention to read and suggest and explain MAC &
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13 years 9 months ago #36562
by truesdq
simplest
MY QUESTION WAS ===> considered LAN environment where we use both ip and mac addresses if switches don't take care of ip so why we use ip addresses...
someone might say for management purposes which is exceptional
if ip addresses removed then no communication would be possible although MAC addresses are
Anyone will explain me with some examplez?
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The ans i have gotten from some1 else was put below===>
Ok... I think the question is... if we only rely MAC addresses to get from one machine to another on a network, then why do we use IP addresses?
Simple answer:
We don't - unless we are communicating from one IP host to another. An application sends it's data/command down through the TCP/IP stack. The TCP/UDP header is placed on the data and then it is sent down to IP. Since we don't really need the IP address information to get from one local host to another, this should be an optional step - it is not optional, however as this is "TCP/IP" we are going through and the application doesn't know if the target is local (found via MAC address only) or remote (found via network address, e.g., IP). So... the IP header is applied to the packet as if it may be going to another network. The MAC header is applied finally with a type field value of 0x0800 indicating an IP header follows and the packet is sent out.
Upon receipt, a host will check the destination MAC address to see if the packet is addressed to that host. If yes, the MAC header will be stripped off and the remainder handed up to IP (remember that 0x0800 designation?). IP will check the IP header to see if the packet is addressed to the local IP address, broadcast or a multicast address accepted by the local host. If OK, then IP will strip off the IP header and hand the remaining portion up to the transport layer - TCP or UDP. Same "stripping off the header" happens there before the data is passed up to the receiving application.
So... the bottom line is. The IP header/addressing is absolutely necessary when communicating on a single network, but the sender doesn't know that and the receiver doesn't know if the packet came from a local machine or through a router. That IP header/addressing enables us to communicate through an internetwork.
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And what i caught from her ans i have written below===>
I catch from your ans that switch usually doesn't care for IP addresses , only it needs ip addresses for MAC table (ARP/RARP) and other management purposes.As the switch will always decide on the basis of MAC for sending and receiving Data/frame/s.
And as the usual way of the host considered computer's machines when it communicated either with local host or remote, the data which to be sent, would passed through the 7 layers and where in transport layer the TCP/UDP information is attached with ip header and the sender (computer) wouldn't know either the data will be received by local host( other computer) or remote host, that is why it is added.
What you think TCP/UDP wouldn’t be used on single network ( LAN) which will responsible for delivering data. i-e The 3 handshake and 4 handshake wouldn’t be on LAN.
_______________________________________________
That I have gotten from your written. Maybe what I caught from your explanation, would be wrong .If so, I will request you once again to explain me please …
Anyway I was developing some idea!
______________________________________________
If you have read all that...
I need u tell me about her ans, either correct or not ? and what i have taken idea is correct ? and if my idea is wrong then please please make it correct and
what u concluded from her ans
if she exactly correct then please help me to make it clear .
please please please....
someone might say for management purposes which is exceptional
if ip addresses removed then no communication would be possible although MAC addresses are
Anyone will explain me with some examplez?
_______________________________________________
The ans i have gotten from some1 else was put below===>
Ok... I think the question is... if we only rely MAC addresses to get from one machine to another on a network, then why do we use IP addresses?
Simple answer:
We don't - unless we are communicating from one IP host to another. An application sends it's data/command down through the TCP/IP stack. The TCP/UDP header is placed on the data and then it is sent down to IP. Since we don't really need the IP address information to get from one local host to another, this should be an optional step - it is not optional, however as this is "TCP/IP" we are going through and the application doesn't know if the target is local (found via MAC address only) or remote (found via network address, e.g., IP). So... the IP header is applied to the packet as if it may be going to another network. The MAC header is applied finally with a type field value of 0x0800 indicating an IP header follows and the packet is sent out.
Upon receipt, a host will check the destination MAC address to see if the packet is addressed to that host. If yes, the MAC header will be stripped off and the remainder handed up to IP (remember that 0x0800 designation?). IP will check the IP header to see if the packet is addressed to the local IP address, broadcast or a multicast address accepted by the local host. If OK, then IP will strip off the IP header and hand the remaining portion up to the transport layer - TCP or UDP. Same "stripping off the header" happens there before the data is passed up to the receiving application.
So... the bottom line is. The IP header/addressing is absolutely necessary when communicating on a single network, but the sender doesn't know that and the receiver doesn't know if the packet came from a local machine or through a router. That IP header/addressing enables us to communicate through an internetwork.
_________________________________________
And what i caught from her ans i have written below===>
I catch from your ans that switch usually doesn't care for IP addresses , only it needs ip addresses for MAC table (ARP/RARP) and other management purposes.As the switch will always decide on the basis of MAC for sending and receiving Data/frame/s.
And as the usual way of the host considered computer's machines when it communicated either with local host or remote, the data which to be sent, would passed through the 7 layers and where in transport layer the TCP/UDP information is attached with ip header and the sender (computer) wouldn't know either the data will be received by local host( other computer) or remote host, that is why it is added.
What you think TCP/UDP wouldn’t be used on single network ( LAN) which will responsible for delivering data. i-e The 3 handshake and 4 handshake wouldn’t be on LAN.
_______________________________________________
That I have gotten from your written. Maybe what I caught from your explanation, would be wrong .If so, I will request you once again to explain me please …
Anyway I was developing some idea!
______________________________________________
If you have read all that...
I need u tell me about her ans, either correct or not ? and what i have taken idea is correct ? and if my idea is wrong then please please make it correct and
what u concluded from her ans
if she exactly correct then please help me to make it clear .
please please please....
simplest
13 years 9 months ago #36566
by sose
sose
Network Engineer
analysethis.co/index.php/forum/index
Replied by sose on topic Re: needed ur attention to read and suggest and explain MAC &
You are supposed to trace the initial trend on this topic and make this post.
sose
Network Engineer
analysethis.co/index.php/forum/index
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13 years 9 months ago #36567
by truesdq
simplest
Replied by truesdq on topic Re: needed ur attention to read and suggest and explain MAC &
hmmm i scanned from initial to final, but i couldn't either catch or conclude ...
please looking forward to responding here
please looking forward to responding here
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- Posts: 90
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13 years 9 months ago #36586
by truesdq
simplest
Replied by truesdq on topic Re: needed ur attention to read and suggest and explain MAC &
i am still looking for any1 response to comments and help me regurding the asken Question please
simplest
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