CompTIA A+ 220-1201 (2.6 - IPv4 and IPv6)

IP addressing

• IPv4 is the primary protocol for everything we do

- You probably won't configure anything else

• IPv6 is now part of all major operating systems

- And the backbone of our Internet infrastructure

IPv4 addresses

• Internet Protocol version 4

- OSI Layer 3 address

Public IPv4 addresses

• Each IPv4 address on the Internet is unique

- 1.1.1.1 can communicate to 2.2.2.2

• It is estimated that there are over 20 billion devices connected to the Internet (and growing)

- IPv4 supports around 4.29 billion addresses

- There's an obvious scalability issue

• We've found ways to manage the demand

- Network Address Translation (NAT)

IPv4 addresses format

8 bits = 1 byte = 1 octet

32 bits = 4 bytes

IPv6 addresses format

16 bits = 2 bytes = 2 octets

128 bits = 16 bytes

RFC 1918 private IP addresses

Private IP address ranges

• Large private IP address ranges

- Properly design and scale large networks

• Private IP addresses are not Internet-routable

- But can be routed internally

- Use NAT for everything else

• Defined in RFC 1918

- Request for Comment

IPv6 addresses

• Internet Protocol v6 - 128-bit address

- 340,282,366,920,938,463,463,374,607,

431,768,211,456 addresses (340 undecillion)

- 6.8 billion people could each have

5,000,000,000,000,000,000,000,000,000 addresses

• Your DNS is very important!

• First 64 bits is generally the network prefix (/64)

• Last 64 bits is then the host network address