14 - 1 - 3 - 4
15  -  1
16 - adresse mac det == ( son @MAC or mac broadcast ff.ff.ff.ff.ff.ff)
17 - 4
18 - 172.30.10.255 - 172.30.10.129 -> 172.30.10.254
20 - 1 2 3 1 3 3
21 - 172.16.0.0 -> 172.31.255.255
22 - 124.120.16.0
23 - 64 - 255.255.252.0
24 - 2 ^ 8 = 1024
25 - controle de flux
28 - 6 octet
29 - reseau 1 : 192.168.0.0/26
	reseau 2 : 192.168.0.96/30
	reseau 3 : 192.168.0.64/27