IP Addressing

 

5.0 IP Addressing & Subnetting

Detailed IP addressing scheme using Variable Length Subnet Masking (VLSM) to efficiently allocate IP addresses for different network segments.

Network Requirements:

We have been assigned the Class C private network address 192.168.10.0/24. We need to create subnets for the following groups:

Public WiFi (Guest) – Requires: 30 hosts

Client PCs (Gamers) – Requires: 20 hosts

Admin & Servers – Requires: 5 hosts

VLSM Calculation Steps

Step 1: Subnet for Public WiFi (Largest Requirement) Needed: 30 hosts Formula:  2^n − 2 ≥ 30 2^5 − 2 = 30  (Exact match, but usually need room for growth/gateway, so 2^6 is safer) Let's use 2^6 =64 addresses. Bits borrowed (host): 6 bits Network bits: 32 − 6 = / 26 Subnet Mask:  255.255.255.192 (/26)

Step 2: Subnet for Client PCs Needed: 20 hosts Next available IP: 192.168.10.64 Formula: 2^n − 2 ≥ 20 2^5 − 2 = 30 hosts available. Block size: 32 addresses Bits borrowed (host): 5 bits Network bits: 32−5=/27 Subnet Mask:  255.255.255.224 (/27)

Step 3: Subnet for Admin & Servers Needed: 5 hosts Next available IP:  192.168.10.96 Formula: 2^n − 2 ≥ 5 2^3 − 2 = 6 hosts available (Tight fit). Let's use 2^4 =16 addresses for future expansion. Block size: 16 addresses Bits borrowed (host): 4 bits Network bits: 32−4=/28 Subnet Mask:  255.255.255.240 (/28)

Final IP Allocation Table

Subnet Name	Network Address	CIDR	Subnet Mask	Usable Host Range	Broadcast Address
Public WiFi	192.168.10.0	/26	255.255.255.192	192.168.10.1  – 192.168.10.62	192.168.10.63
Client PCs	192.168.10.64	/27	255.255.255.224	192.168.10.65 – 192.168.10.94	192.168.10.95
Admin & Servers	192.168.10.96	/28	255.255.255.240	192.168.10.97 – 192.168.10.110	192.168.10.111