Overview
This session covers how IPv4 addresses are structured, the difference between network and host portions, and the role of subnet masks.
IPv4 Address Structure
- An IPv4 address is 32 bits, shown in dotted decimal (e.g., 192.168.123.132).
- It has two parts:
- Network part: identifies the network.
- Host part: identifies a device within that network.
- All devices on the same network share the network part but have unique host parts.
Subnet Mask
- A subnet mask is a 32-bit number, also in dotted decimal format.
- It shows which part of the IP address is the network and which is the host.
- '1's in the mask mark the network portion; '0's mark the host portion.
How to Separate Network and Host Portions
- Line up the IP address and subnet mask bit by bit.
- Example: With IP 192.168.123.132 and subnet mask /24 (255.255.255.0):
- First 24 bits (network): 192.168.123.0
- Last 8 bits (host): 132
Key Terms
- IPv4 Address: Unique 32-bit number for a device.
- Network Part: Identifies the network.
- Host Part: Identifies the device.
- Subnet Mask: Shows which bits are network/host.
- /24: Subnet mask with 24 network bits (255.255.255.0).
Next Steps
- Review how subnet masks separate network and host parts.
- Get ready to learn about IP address classes next.