Assume that hosts A and B enjoy a TCP nouns established. Assume that the two hosts are separated by one router (i.e. they are one hop apart).Why does host A at one remove use the MAC (LAN) address of host B when constructing its packet to convey to host B?
Answers:
A Mac address does not contain any routing information, so a router cannot determine which segment to transport the message to. An ip address does contain routing information. It have a meet people section and a local address factor, so a router can read the make friends factor of the address and route the message to the appropriate segment.
Because the PROTOCOL is Tcp/Ip so that`s why you distribute
header info as an IP Address.
This would consequently be routed according to your routers / gateways rules to Lan B.
IPX/SPX Protocol used to use Mac Addresses I expect.
Because routers separate broadcast domains. Routers strip sour the division 2 information (i.e. MAC header) to catch at the shroud 3 information (IP header) smart to direct the IP datagram to the proper subnet.
Routers are primarily used to connect different types of band 2 networks together. I.e. connect an Ethernet LAN to DSL WAN.