destination/source Mac address changed...need refreshing
say i need some refreshing on this.
you have a computer A sending a message to Computer B who is in a another subnet seperated by one router.
The IP address of the Source and Destination computers dont change but the Mac addresses does. Now I read that the router will take away the source MAC address of computer A and put the MAC address of the interface that that Computer B resides on, making that the new MAC address. Now after that the router will take the Destination MAC address which is the interface of Computer A, take it away put the MAC address of Computer B!
Im I correct?
If so, then what about Computer A having the MAC address of Computer B to begin with, cant that be a possibility? And if that is true then the router wont do any stripping of MAC addresses, Only the Source MAC address will change of Computer A to the interface of Computer B.
Im I correct in this one as well.
you have a computer A sending a message to Computer B who is in a another subnet seperated by one router.
The IP address of the Source and Destination computers dont change but the Mac addresses does. Now I read that the router will take away the source MAC address of computer A and put the MAC address of the interface that that Computer B resides on, making that the new MAC address. Now after that the router will take the Destination MAC address which is the interface of Computer A, take it away put the MAC address of Computer B!
Im I correct?
If so, then what about Computer A having the MAC address of Computer B to begin with, cant that be a possibility? And if that is true then the router wont do any stripping of MAC addresses, Only the Source MAC address will change of Computer A to the interface of Computer B.
Im I correct in this one as well.
There There, Its okay to feel GUILTY...........There is no SIN in PLEASURE!
Comments
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Jiggsaww
Member Posts: 195
hmmm thaz for N+ now i even more convinced that CCNA and Net+ go hand in hand......let me c the sybex book says that that if comp a sends a message to comp b, the ip woulds always b that of comp b but the mac address will be that of the router, i think, then d router takes that encaped data seeing d ip and realise it's for comp b replaces the mac with that of comp b.......is this the same ting as wat u said? -
x_Danny_x
Member Posts: 312 ■■□□□□□□□□
yes, the mac address of the router would be of the interface Computer B resides on (which will be the new source) and the MAC of Computer B will be the new destination MAC addressed.
Now, cant Computer A already have the destination MAC addressed of Computer B to begin with? So when the router gets the message, it will only change the Source MAC addressed of Computer A to the new source which will be the interface MAC Addressed that Computer B resides on!
Is that possible?There There, Its okay to feel GUILTY...........There is no SIN in PLEASURE! -
Jiggsaww
Member Posts: 195
u mean on it's way back?......cause i don't find it make sense to change the source mac if comp b not sending something back.......
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Gogousa
Member Posts: 68 ■■□□□□□□□□
Computer A is not aware of the MAC address of computer B because computer B is on another subnet. One subnet is not aware of the mac table of another subnet.
I'm not sure if I understud your question.