🌐 Static vs Dynamic IP & DHCP

1. Static IP

• Definition: An IP address that is manually assigned to a device and does not change.
• Characteristics:
  • Permanent, fixed address.
  • Often used for servers, printers, or devices that must always be reachable at the same IP.
• Pros: Reliable for hosting websites, remote access, or networked devices.
• Cons: Requires manual setup, less flexible, can expose devices to security risks if not managed properly.

2. Dynamic IP

• Definition: An IP address that is automatically assigned by a DHCP server and may change over time.
• Characteristics:
  • Temporary, changes when devices reconnect or after a lease expires.
  • Commonly used for home users and mobile devices.
• Pros: Easier to manage, conserves IP addresses, more secure (harder to target).
• Cons: Not suitable for servers or services that need a consistent address.

3. DHCP (Dynamic Host Configuration Protocol)

• Definition: A network protocol that automatically assigns IP addresses and other configuration details (like subnet mask, gateway, DNS) to devices on a network.
• How it works:
  1. Device connects to the network.
  2. Sends a request (DHCP Discover).
  3. DHCP server offers an IP (DHCP Offer).
  4. Device accepts (DHCP Request).
  5. Server confirms (DHCP Acknowledge).
• Benefits:
  • Simplifies network management.
  • Prevents IP conflicts.
  • Supports both dynamic and static reservations (you can reserve a fixed IP for specific devices).

4. Putting It Together

• Static IP: Fixed, set manually. Best for servers.
• Dynamic IP: Assigned automatically, changes over time. Best for everyday devices.
• DHCP: The system that manages dynamic IP assignment, but can also reserve static IPs if needed.

5. Example

• Home Wi‑Fi: Your router uses DHCP to give your phone a dynamic IP (e.g., 192.168.1.12).
• Office printer: IT sets a static IP (e.g., 192.168.1.50) so everyone can always find it.
• Web server: Needs a static public IP (e.g., 203.0.113.25) so clients can connect reliably.

✅ Summary:

• Static IP = fixed, manual, reliable for servers.
• Dynamic IP = automatic, flexible, common for users.