linker layer

what is

1. solve how to transimit data in a LAN, which work closely with pyhsical layer detail 1. divide data into ethernet frame 2. transmit data to the device through medium

2. Ethernet frame [ mac header 14 byte] [[source mac][target mac] [type]][payload] [checksum]

3. trasmission

4. mtu max transmission unit; range: 64-1518bytes;

switch