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Encapsulation/Decapsulation question.
bbarrick
Member Posts: 242 ■■■□□□□□□□
in CCNA & CCENT
In the book I'm reading, the way it describes the process of a frame reaching a router from it's source and being passed on to it's next destination as if the source address and destination address is changed each time. So a packet leaving PC1 to R1 would have the address of PC1 as it's source and R1 as it's destination. Once it reaches R1, it makes it seem as though those addresses are dropped and the new source address is R1's and the new destination would be say, R2 before it then goes on to say PC2.
To me this doesn't really make a whole lot of sense, PC1 and PC2's addresses have to stay in the frame as the original source and final destination right?
To me this doesn't really make a whole lot of sense, PC1 and PC2's addresses have to stay in the frame as the original source and final destination right?
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pamccabe
Member Posts: 315 ■■■□□□□□□□
Correct, the Layer 3 address would not change. The Layer 2, Ethernet addresses, would change. The router would strip the packet of the frames and then put new frames on with new source and destination Layer 2 addresses. Then forward the packet on.In the book I'm reading, the way it describes the process of a frame reaching a router from it's source and being passed on to it's next destination as if the source address and destination address is changed each time. So a packet leaving PC1 to R1 would have the address of PC1 as it's source and R1 as it's destination. Once it reaches R1, it makes it seem as though those addresses are dropped and the new source address is R1's and the new destination would be say, R2 before it then goes on to say PC2.
To me this doesn't really make a whole lot of sense, PC1 and PC2's addresses have to stay in the frame as the original source and final destination right? -
Optionsbbarrick
Member Posts: 242 ■■■□□□□□□□
The layer 3 being the network source and destination address and encapsulated as a packet right within the frame? Just making sure I get the wording/terminology down. That makes sense, I forgot to look at it that way. So once a frame reaches PC2 it no longer has any trace of being at R1? I guess data coming from PC2 and going back to PC1 could take an entirely different path unless it's on a Point to Point WAN right?