IP Address Facts Flashcards

IP Address Overview

• An IP address is a 32-bit binary number allowing hosts to participate in IP-based networks.
• Represented as four octets, each octet is an 8-bit number, separated by periods.

Representation of IP Address

• Can be displayed in two formats: Decimal or Binary.
• In decimal notation, each octet ranges from 0 to 255.
• Binary notation consists of 8-character numbers representing each octet.

Conversion of IP Addresses

• To convert from binary to decimal, assign decimal values based on binary positions; for instance, 10000000 equals 128.
• The decimal equivalent of binary 10010101 is calculated as 128 + 16 + 4 + 1 = 149.

Components of an IP Address

• An IP address includes both network and host addresses.
• The subnet mask is a 32-bit number that identifies the network portion in an IP address.

Subnet Masks

• Always presented in binary as a series of 1's followed by 0's, e.g., 255.255.255.0.

Classes of IP Addresses

• Class A:
  • Range: 1.0.0.0 to 126.255.255.255
  • Subnet Mask: 255.0.0.0
  • Supports up to 16,777,214 hosts.
• Class B:
  • Range: 128.0.0.0 to 191.255.255.255
  • Subnet Mask: 255.255.0.0
  • Supports up to 65,534 hosts.
• Class C:
  • Range: 192.0.0.0 to 223.255.255.255
  • Subnet Mask: 255.255.255.0
  • Supports up to 254 hosts.
• Class D:
  • Range: 224.0.0.0 to 239.255.255.255
  • Used for multicast groups, no default subnet mask.
• Class E:
  • Range: 240.0.0.0 to 255.255.255.255
  • Reserved for experimental use, no default subnet mask.

Network and Broadcast Addresses

• The first address in a range identifies the network; all host bits are 0's.
• The last address is the broadcast address, sending messages to all hosts; all host bits are 1's.

Host Addresses

• Each host requires a unique IP address within the same network portion.
• First and last addresses in any range are reserved for network and broadcast purposes.
• Example host ranges:
  • Class A: 115.0.0.1 to 115.255.255.254
  • Class B: 154.90.0.1 to 154.90.255.254
  • Class C: 221.65.244.1 to 221.65.244.254.

Local Host Addressing

• Addresses in the 127.0.0.0 range refer to the local host, with 127.0.0.1 as the loopback address.

IP Address Management

• Unique IP addresses on the Internet are controlled by organizations.
• The Internet Assigned Numbers Authority (IANA) oversees IP address assignments.
• IANA operates under ICANN and allocates IP address blocks to Regional Internet Registries (RIRs), which in turn distribute them to Internet Service Providers (ISPs).