What changes the link-layer address of the packet when it forwards the packet?

Kenrick

Hi Network Experts,
I think the answer for the following question is switch because it operates at the link layer, please let me know if I am wrong.

A ___________ changes the link-layer address of the packet when it forwards the packet.

a)router

b)switch

c)hub

Dimithri

I'm not a Network expert, But I thought I would try to answer your question to the best of my abilities. Your Answer Switch is correct in the current time 2015. Hub is also used and it is just a repeater. However it is an outdated device though still in use. But in terms of the Latest Exams that answer will not be correct. The hub is considered Layer 1 device according to the OSI Model and Switch is considered a Layer 2 device.

OctalDump

What device changes a link layer address? Why would the link layer address need to change?

A link layer address will change when the packet moves from one segment to another. It might be from one LAN to a different LAN, or from a LAN to WAN (eg from an ethernet to an ATM network) or any other kind of change where the network changes at the link layer (layer 2). Since the change is at layer 2, layer 3 and above are unaffected, the IP address will remain the same.

So, the question is really, why would the link layer address (the layer 2 address, eg the MAC address) change? What device would need to change that address?