Ethernet Lan Switching

1.which device use to connect separate Lans?

2.what 3 sections we can seaprate ethernet frame?

3.expalin five fields in ethernet header section?

5.what is ethernet trailer?

6.what are the 2 parts we can seprate mac address?

7.how many bits have mac address?

5.what is BIA address?

6.what is OUI?

7.what is broadcast frame , unicast frame , unknown frame  ?

8.explain how switches identify mac adddress dynamicaly?

9.what is preamble , SFD , fcs ? 

10.how to identify in ethernet framing whether packet contains ipv4 or ipv6 protocol?