/24

/16  net  IP
/18  2 * 2^14-2
/19  6 * 2^13-2
/20  14* 2^12-2
...
/24  254*254
...
/30 2^14-2  2
		 /17 255.255.128.0  /25 255.255.255.128
/10 255.192.0.0	 /18 255.255.192.0  /26 255.255.255.192
/11 255.224.0.0	 /19 255.255.224.0  /27 255.255.255.224
/12 255.240.0.0	 /20 255.255.240.0  /28 255.255.255.240
/13 255.248.0.0	 /21 255.255.248.0  /29 255.255.255.248
/14 255.252.0.0	 /22 255.255.252.0  /30 255.255.255.252
/15 255.254.0.0  /23 255.255.254.0
/16 255.255.0.0	 /24 255.255.255.0

/8  10.255.255.255

                10.1.1.1
AND      1111 1111.0.0.0
--------------------------
 network number 10.0.0.0
 broadcast = 10.255.255.255

/10 10.63.255.255
	       10.        1.1.1
AND	1111 1111.1100 0000.0.0
--------------------------------
network number 10.	  0.0.0
  range 2^22=2^8*2^8*2^6
  increment = 2^6 in second octet
  10.0.0.0 ~ 10.63.255.255
  10.64.0.0
  10.128.0.0
  10.192.0.0
borrowing /10-/8=2 bits
creating 2^2 subnets
increment 256/4=64

CSMA/CD
Carrier Sense Multi Access/Collision Detection
  
  listen before talk
  listen while talking
  wait before talk again




/12 10.15.255.255

/14 10.3.255.255

/22 10.1.3.255
    10.1.1.1 255.255.252.0
network number 10.1.0.0
 range 2^10=2^8*2^2
 increment in 3rd octet=4
 10.1.4.0 ==> 10.1.3.255

/29 10.1.1.7

  8 ports = 7! repeaters

Exer 8: 
128.1.2.3/29 ==> 128.1.2.7

32-29=3  2^3=8

128.1.2.0 ~ 128.1.2.7
128.1.2.8

128.1.0.0/16
128.1.0.0/29 = 128.1.0.0 ~ 128.1.0.7
	       128.1.255.248 ~ 128.1.255.255

16.65.0.0/15 16.64.255.255/15
16.0.0.0/8
borrow 15-8=7
subnets = 2^7
increment = 2
16.0.0.0/15  ~ 16.1.255.255
16.2.0.0/15  ~ 16.3.255.255
...
16.64.0.0/15 ~ 16.65.255.255
...
16.254.0.0/15 ~ 16.255.255.255