Network Address & Broadcast Address

Network Address & Broadcast Address

• Network Address merupakan alamat pertama
• Broadcast Address merupakan alamat terakhir

Network addresss	Broadcast address
1st address	Last address
10.0.0.0	10.255.255.255
172.16.0.0	172.31.255.255
192.168.0.0	192.168.255.255

192.168.100.10
255.255.255.0
192.168.100.0 <- network address
192.168.100.255 <- broadcase address

Class IP	Octet 1	Octet 2	Octet 3	Octet 4
A	Network ID	Host ID	Host ID	Host ID
	8 Byte	8 Byte	8 Byte	8 Byte
B	Network ID	Network ID	Host ID	Host ID
	8 Byte	8 Byte	8 Byte	8 Byte
C	Network ID	Network ID	Network ID	Host ID
	8 Byte	8 Byte	8 Byte	8 Byte

CIDR (CLASSLESS INTER DOMAIN ROUTING)

class	Default subnetmask	Net address	Host address	CIDR
	w.x.y.z
A	255.0.0.0	w	x.y.z	8
B	255.255.0.0	w.x	y.z	16
C	255.255.255.0	w.x.y	z	24

Contoh Pengiraan 1:
default subnetmask : 192.168.100.1/ 31(tentukan class terlbih dhulu)

                                255.255.255.0 (class C)
                                11111111.11111111.11111111.11111110
2^{n(lebihan bit network dlm host octet)}=2⁷ = 128 network ID
2^{n(bilangan bit host dlm host octet)}=2¹ = 2-2 = 0 usable host 

Contoh Pengiraan 2 :

181.17.30.6 

subnet mask = 1000

default subnet mask 16 (255.255.0.0)class B

11111111.11111111.11111111.11000000

CIDR = host

2ⁿ= 2¹⁰ = 1024 network ID

2ⁿ= 2⁶ = 64-2 = 62 usable host

Contoh pengiraan 3 :


192.168.30.0/x

Diberi subnet @ network = 32

Cari x dan host ID

255.255.255.0

11111111.11111111.11111111.11111000

CIDR = 24 + 5 = 29

 2ⁿ = 32

 2⁵ = 32 Network ID

  2³ = 8 – 2 = 6 host