Subnetting VLSM dengan Network: 192.168.10.0/25

VLSM — Soal & Solusi: 192.168.10.0/25

📌 Soal VLSM

Network: 192.168.10.0/25

• Subnet A = 60 host
• Subnet B = 24 host
• Subnet C = 12 host
• Subnet D = 5 host

🧮 Step 1 & 2: Tentukan Prefix & Urutkan

Rumus: Jumlah host usable = 2^(32 - prefix) - 2

Subnet	Host Needed	Prefix Needed	Usable Hosts
A	60	/26	62
B	24	/27	30
C	12	/28	14
D	5	/29	6

Urutkan dari terbesar → terkecil: A → B → C → D

📌 Step 3: Alokasi Subnet

Blok awal: 192.168.10.0/25 (0–127)

Subnet	Prefix	Network	Usable Range	Broadcast
A (60 host)	/26	192.168.10.0	192.168.10.1 – 192.168.10.62	192.168.10.63
B (24 host)	/27	192.168.10.64	192.168.10.65 – 192.168.10.94	192.168.10.95
C (12 host)	/28	192.168.10.96	192.168.10.97 – 192.168.10.110	192.168.10.111
D (5 host)	/29	192.168.10.112	192.168.10.113 – 192.168.10.118	192.168.10.119
Cadangan	/29	192.168.10.120	192.168.10.121 – 192.168.10.126	192.168.10.127

Catatan: Total yang dipakai oleh A+B+C+D = 120 alamat. /25 = 128 alamat → masih ada 8 alamat cadangan.

🌳 Step 4: Diagram Visual / Tree

192.168.10.0/25 (0 - 127)
├─ [A] 192.168.10.0/26   (0  - 63)   -> 64 addr (usable 1-62)   -> 60 host
├─ [B] 192.168.10.64/27  (64 - 95)   -> 32 addr (usable 65-94)  -> 24 host
├─ [C] 192.168.10.96/28  (96 - 111)  -> 16 addr (usable 97-110) -> 12 host
└─ [D] 192.168.10.112/29 (112-119)   -> 8 addr  (usable 113-118) -> 5 host
    └─ Cadangan: 192.168.10.120/29 (120-127)

📊 Step 5: Tabel Ringkas

Subnet	Prefix	Network	Usable Range	Broadcast	Total Addr	Usable Hosts
A	/26	192.168.10.0	192.168.10.1-62	192.168.10.63	64	62
B	/27	192.168.10.64	192.168.10.65-94	192.168.10.95	32	30
C	/28	192.168.10.96	192.168.10.97-110	192.168.10.111	16	14
D	/29	192.168.10.112	192.168.10.113-118	192.168.10.119	8	6

Gateway rekomendasi: gunakan alamat usable pertama setiap subnet (mis. A → 192.168.10.1, B → 192.168.10.65, C → 192.168.10.97, D → 192.168.10.113).