Frame addresses as it traverses Network

Feb 20, 2005 3 Replies
Frame addresses as it traverses Network open original image

When a host communicates with another host with a router separating them (between them), do the host use each others MAC address as the source and destination addresses, or do they use the MAC address of the Routers port that they are connected to? Hoping for "routers MAC address" as answer.

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Leeds me to believe the hosts use the MAC address of the routers interface, but this may be for a special situation when useing proxy arp. Other online sources state "Even thoe the frames are passing through a router, the source and destination MAC addresses will not change during the data transmission. They indicate the frame will contain the destination and source address of the respective host. If the answer is in the Sybex or Boson books, I couldnt find it.



Please help.



Steve C.


MAC addresses stay on the subnet. So when your talking to a PC across a router, your PC will use the router's mac as the destination address. The other PC will see the packet *coming from* the router's mac address.

Just to clarify,

Please view in a fixed-width font such as Courier.

/---\\ ------------------>>>>>

|PC-A | +-----------+--------+ | | | DEST MAC |SRC MAC | ------| \\---/ | E0 MAC |PC-A | | +-----------+--------+ | | | | +-------+ ------>|RTR -E0| | | | | |------|RTR -E1| | +-------+ | |

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