LAN
area small (geography - campus)
speed moderate (1Mbps, 10Mbps)
communicate each other without a third party's help

bridge/switch functions
learning (from incoming MA)
forwarding (to a different port)
filtering (to drop the frame)
buffering (asymetric networks (different speeds))

swithes kinds
cut-through  (check DA only)
store-and-forward  (check entire frame)
fragment-free (check up to before data)

POP (Point of Presence, where to go out)
MDF (Main room, should be near center of everything(all IDF's if any))
IDF (branch closets, as needed)

10.2.2.2

/24	256
/23	512
/22	1024
/21	2048
/29	8
/25	128
/27	32
/28	16
WAN
any traffic that needs ISP's help
geography across cities