Subnetting

pertama tama, range ip dahulu

seperti yg terlihat, bahwa 128 + 64 + 32 + 16 + 8 + 4 + 2 + 1 = 255

contoh 192.168.10.0/24:

ada network 192.168.10.0/24, kita ingin bagi jadi 4 jaringan. maka 256 / 4 = 64 hosts, dan ini akan

pembagian nya

network 1: 192.168.10.0, broadcast: 192.168.10.63, range ip yang usable: 192.168.10.1 - 192.168.10.62
network 2: 192.168.10.64, broadcast: 192.168.10.127, range ip yang usable: 192.168.10.65 - 192.168.10.126
network 3: 192.168.10.128, broadcast: 192.168.10.191, range ip yang usable: 192.168.10.129 - 192.168.10.190
network 4: 192.168.10.192, broadcast: 192.168.10.255, range ip yang usable: 192.168.10.193 - 192.168.10.254

origin: pakai acuan ip kelas c

jumlah hosts, misal cidr 24, itu max nya 256 kalau 0b11111111, kenapa 0b10000000 itu 128, dan kenapa 0b11000000 itu 192

ok, lalu kenapa jika cidr /26, itu 255.255.255.192, punya 64 hosts, 4 network. semua ini didapat dari (max int case ini 8 bit) / maxint - pad network

ini start dari /24

0b00000000 -> 0 (katakanlah octet ke 4, cidr 24) // 1 network
0b10000000 -> 0 (cidr 25, 128 hosts) // 2 network
0b11000000 -> 0 (cidr 26, 128 + 64) // 4 network
0b11100000 -> 0 (cidr 27, 128 + 64 + 32) // 8 network
0b11110000 -> 0 (cidr 28, 128 + 64 + 32 + 16) // 16 network
0b11111000 -> 0 (cidr 29, 128 + 64 + 32 + 16 + 8) // 32 network
0b11111100 -> 0 (cidr 30, 128 + 64 + 32 + 16 + 8 + 4) // 64 network
0b11111110 -> 0 (cidr 31, 128 + 64 + 32 + 16 + 8 + 4 + 2) // 128 network
0b11111111 -> 0 (cidr 32, 128 + 64 + 32 + 16 + 8 + 4 + 2 + 1) // 256 network

start dari /16

0b0000000000000000 -> 0 (cidr 16, 65535) // 1 net, 65535 hosts
0b1000000000000000 -> 0 (cidr 17, 65535 + ) // 2 net, 32767 hosts
0b1100000000000000 -> 0 (cidr 26, 128 + 64) // 4 net
0b1110000000000000 -> 0 (cidr 27, 128 + 64 + 32) // 8 net
0b1111000000000000 -> 0 (cidr 28, 128 + 64 + 32 + 16) // 16 net
0b1111100000000000 -> 0 (cidr 29, 128 + 64 + 32 + 16 + 8) // 32 net
0b1111110000000000 -> 0 (cidr 30, 128 + 64 + 32 + 16 + 8 + 4) // 64 net
0b1111111000000000 -> 0 (cidr 31, 128 + 64 + 32 + 16 + 8 + 4 + 2) // 128 net
0b1111111100000000 -> 0 (cidr 32, 128 + 64 + 32 + 16 + 8 + 4 + 2 + 1) // 256 net

-- stagging (perhitungan ip cidr 16 keatas) max int 16 bit: 65536

/16 : 0b0000000000000000 = 0
/17 : 0b1000000000000000 = 32768, maka 65536 / 32768 = 2, alias 2 network, 32768 hosts
/18 : 0b1100000000000000 = 49152, maka 65536 / (65536 - 49152) = 4 network, 16384 hosts,
/19 : 0b1110000000000000 = 57344, maka 65536 / (65536 - 57344) = 8 network, 8192 hosts,
/20 : 0b1111000000000000 = 61440, maka 65536 / (65536 - 61440) = 16 network, 4096 hosts,
/21 : 0b1111100000000000 = 61440, maka 65536 / (65536 - 61440) = 32 network, 2048 hosts,
/22 : 0b1111110000000000 = 64512, maka 65536 / (65536 - 64512) = 64 network, 1024 hosts,
/23 : 0b1111111000000000 = 64512, maka 65536 / (65536 - 64512) = 128 network, 512 hosts,
/24 : 0b1111111100000000 = 64512, maka 65536 / (65536 - 64512) = 256 network, 256 hosts,

-- stagging cidr 8 keatas max int int 24 bit: 16777216

/9 : 0b100000000000000000000000 = 16777216 / (16777216 - 8388608) = 2 network, 8388608 hosts
/10: 0b110000000000000000000000 = 16777216 / (16777216 - 12582912)= 4 network, 4194304 hosts
/11: 0b111000000000000000000000 = 16777216 / (16777216 - 14680064)= 8 network, 2097152 hosts
/12: 0b111100000000000000000000 = 16777216 / (16777216 - 15728640)= 16 network, 1048576 hosts
/13: 0b111110000000000000000000 = 16777216 / (16777216 - 16252928)= 32 network, 524288 hosts
/14: 0b111111000000000000000000 = 16777216 / (16777216 - 16515072) = 64 network, 262144 hosts
/15: 0b111111100000000000000000 = 16777216 / (16777216 - 16646144) = 128 network, 131072 hosts
/16: 0b111111110000000000000000 = 16777216 / (16777216 - 16711680) = 256 network, 65536 hosts
/17: 0b111111111000000000000000 = 16777216 / (16777216 - 16744448) = 512 network, 32768 hosts
/18: 0b111111111100000000000000 = 16777216 / (16777216 - 16760832) = 1024 network, 16384 hosts
/19: 0b111111111110000000000000 = 16777216 / (16777216 - 16769024) = 2048 network, 8192 hosts
/20: 0b111111111111000000000000 = 16777216 / (16777216 - 16773120) = 4096 network, 4096 hosts
/21: 0b111111111111100000000000 = 16777216 / (16777216 - 16775168) = 8192 network, 2048 hosts
/9 : 0b100000000000000000000000:

rumusnya: \( 2^{jumlah \space angka \space 1 \space di \space setiap \space padding \space subnet}\)

prefix /19, pad terdekatnya /16, maka dari 16 ke 19 ada 3 angka 1 (0b11100000), maka jumlah subnet yang akan terbentuk adalah 2^3 = 8 subnet
prefix /26, pad terdekatnya 24, maka dari 24 ke 26 ada 2 angka 1 (0b11000000), maka jumlah subnetnya 2^2 = 4

rumusnya: \( 2^{jumlah \space angka \space 0 \space dari \space 32} \)