Configuring IPv4 on a Computer

Important Addresses

1. IP Address

   • Uniquely identifies the device on the network.
   • Example: 192.168.1.165.
   • How other devices send information to your computer.

2. Subnet Mask

   • Example: 255.255.255.0.
   • Used with IP address to determine the local subnet.
   • Helps in routing information locally and to the default gateway.

3. Default Gateway

   • Example: 192.168.1.1.
   • On the same local subnet as the IP address.
   • Routes traffic outside the local subnet.

Additional Settings

• DNS Server
  • Not covered in detail; will be discussed in a future session.

Special IP Addresses

1. Loopback Address

   • Range: 127.0.0.1 to 127.255.255.254.
   • Commonly used: 127.0.0.1.
   • Used to test the IP stack of the local machine.

2. Reserved Addresses

   • Range: 240.0.0.1 to 254.255.255.254.
   • Should not be used on local machines or production networks.

3. Virtual IP Address (VIP)

   • Assigned to logical network adapters, not physical ones.
   • Often used in virtual machines and routers.

IPv4 Address Structure

• Composed of four groups of eight bits each (32 bits total).
• Each group (byte or octet) ranges from 0 to 255.

Automatic IP Address Configuration

1. DHCP (Dynamic Host Configuration Protocol)

   • Automatically assigns IP addresses, subnet masks, gateways, DNS servers, etc.
   • Saves time for network administrators.

2. APIPA (Automatic Private IP Addressing)

   • Range: 169.254.0.1 to 169.254.255.254 (usable: 169.254.1.0 to 169.254.254.255).
   • Assigned when no DHCP server is available.
   • Only communicates within the local subnet (link-local address).
   • Indicates the absence of a DHCP server or a non-functioning DHCP server.