- 1. IP Protocol (Internet Protocol)
- [[#1. IP Protocol (Internet Protocol)#1.1 Definition:|1.1 Definition:]]
- [[#1. IP Protocol (Internet Protocol)#1.2 Key Features:|1.2 Key Features:]]
- [[#1. IP Protocol (Internet Protocol)#1.3 Versions:|1.3 Versions:]]
- 2. IP Address Classes (A, B, C, D, E)
- 3. Broadcast Address
- [[#3. Broadcast Address#3.1 Definition:|3.1 Definition:]]
- [[#3. Broadcast Address#3.2 Characteristics:|3.2 Characteristics:]]
- [[#3. Broadcast Address#3.3 Use Cases:|3.3 Use Cases:]]
- 4. Multicast Address
- [[#4. Multicast Address#4.1 Definition:|4.1 Definition:]]
- [[#4. Multicast Address#4.2 Range|4.2 Range]]
- [[#4. Multicast Address#4.3 Examples:|4.3 Examples:]]
- [[#4. Multicast Address#4.4 Applications:|4.4 Applications:]]
- 5. Network Mask (Subnet Mask)
- [[#5. Network Mask (Subnet Mask)#5.1 Purpose:|5.1 Purpose:]]
- [[#5. Network Mask (Subnet Mask)#5.2 Common Subnet Masks:|5.2 Common Subnet Masks:]]
- [[#5. Network Mask (Subnet Mask)#5.3 Example:|5.3 Example:]]
- 6. Subnetting
- [[#6. Subnetting#6.1 Definition:|6.1 Definition:]]
- [[#6. Subnetting#6.2 Benefits:|6.2 Benefits:]]
- [[#6. Subnetting#6.3 Important Formulae:|6.3 Important Formulae:]]
- [[#6. Subnetting#6.4 Subnetting Example:|6.4 Subnetting Example:]]
- 7. Summary
1. IP Protocol (Internet Protocol)
1.1 Definition:
The Internet Protocol (IP) is a principal protocol in the network layer of the OSI model. It enables communication between computers over a network by addressing and routing packets from source to destination.
1.2 Key Features:
- Connectionless: No prior connection is established before data transfer.
- Best-effort delivery: No guarantee of delivery, ordering, or duplicate protection.
- Packet fragmentation and reassembly.
1.3 Versions:
- IPv4: 32-bit addresses, represented in dotted decimal format. Example: 192.168.0.1
- IPv6: 128-bit addresses, represented in hexadecimal blocks. Example: 2001:0db8::8a2e:0370:7334
2. IP Address Classes (A, B, C, D, E)
- IPv4 addresses are 32-bit numbers, divided into 4 octets (8 bits each).
- Classes are defined based on the starting bits and first octet value.
| Class | Starting Bits | First Octet Range | Default Subnet Mask | Number of Hosts | Typical Use |
|---|---|---|---|---|---|
| A | 0 | 1 – 126 | 255.0.0.0 | ~16 million | Large networks |
| B | 10 | 128 – 191 | 255.255.0.0 | ~65,000 | Medium-sized networks |
| C | 110 | 192 – 223 | 255.255.255.0 | 254 | Small networks |
| D | 1110 | 224 – 239 | Not defined | N/A | Multicasting |
| E | 1111 | 240 – 255 | Not defined | N/A | Research, experimental |
- 127.0.0.0 to 127.255.255.255 is reserved for loopback testing (localhost).
3. Broadcast Address
3.1 Definition:
A broadcast address is used to send data to all devices on a local network (subnet).
3.2 Characteristics:
- Formed by setting all host bits in the IP address to 1.
- It is the highest address in the subnet.
- For example, in 192.168.1.0/24, the broadcast address is 192.168.1.255.
3.3 Use Cases:
Used in protocols like ARP, DHCP to communicate with all hosts.
4. Multicast Address
4.1 Definition:
Multicast is a communication method where data is sent from one source to multiple specific receivers.
4.2 Range
- IPv4 multicast addresses range from 224.0.0.0 to 239.255.255.255 (Class D).
- IPv6 multicast addresses start with the prefix FF00::/8.
4.3 Examples:
- 224.0.0.1 All systems on the local subnet.
- 224.0.0.5: OSPF routers.
4.4 Applications:
Used in IPTV, conferencing, streaming services, and routing protocols.
5. Network Mask (Subnet Mask)
5.1 Purpose:
A subnet mask separates the IP address into network and host portions.
5.2 Common Subnet Masks:
| CIDR Notation | Subnet Mask | Network Bits | Hosts per Subnet |
|---|---|---|---|
| /8 | 255.0.0.0 | 8 | 16,777,214 |
| /16 | 255.255.0.0 | 16 | 65,534 |
| /24 | 255.255.255.0 | 24 | 254 |
| /30 | 255.255.255.252 | 30 | 2 |
5.3 Example:
- IP Address: 192.168.10.20
- Subnet Mask: 255.255.255.0
- Network Portion: 192.168.10
- Host Portion: 20
6. Subnetting
6.1 Definition:
Subnetting is the process of dividing a larger network into smaller logical sub-networks, called subnets.
6.2 Benefits:
- Efficient IP address usage
- Improved network performance
- Enhanced security and control
- Reduced broadcast traffic
6.3 Important Formulae:
- Number of subnets = 2^n (n = number of borrowed bits)
- Hosts per subnet = 2^h - 2 (h = number of host bits; subtract 2 for network and broadcast)
6.4 Subnetting Example:
Given Network: 192.168.1.0/24 (256 total IPs)
To create 4 subnets:
- New subnet mask: /26 (255.255.255.192)
- Each subnet has 64 IPs: 62 usable, 1 network address, 1 broadcast address
| Subnet | Address Range | Usable IP Range | Broadcast Address |
|---|---|---|---|
| 1 | 192.168.1.0/26 | 192.168.1.1 – 192.168.1.62 | 192.168.1.63 |
| 2 | 192.168.1.64/26 | 192.168.1.65 – 192.168.1.126 | 192.168.1.127 |
| 3 | 192.168.1.128/26 | 192.168.1.129 – 192.168.1.190 | 192.168.1.191 |
| 4 | 192.168.1.192/26 | 192.168.1.193 – 192.168.1.254 | 192.168.1.255 |
7. Summary
| Topic | Description |
|---|---|
| IP Address | Unique identifier for devices on a network |
| IP Protocol | Used for addressing and routing data |
| IP Address Classes | Divides IPs into ranges (A–E) based on use and scale |
| Broadcast Address | Address that sends data to all hosts in a subnet |
| Multicast Address | Address used to send data to multiple specific hosts |
| Subnet Mask | Used to identify network and host parts of an IP |
| Subnetting | Technique to divide networks into smaller, manageable parts |