IPv4 Addresses

Question 1

Networking with IPv4

Answer 1

• IP Address, e.g., 192.168.1.165
  
  • Every device needs a unique IP address

• Subnet mask, e.g., 255.255.255.0
• Used by the local device to determine what subnet
it’s on
• The subnet mask isn’t (usually) transmitted across
the network
• You’ll ask for the subnet mask all the time
• What’s the subnet mask of this network?

• Default gateway, e.g., 192.168.1.1
• The router that allows you to communicate outside
of your local subnet
• The default gateway must be an IP address on the
local subnet

Question 2

Special IPv4 addresses

Answer 2

• Loopback address
  
  • An address to yourself
  • Ranges from 127.0.0.1 through 127.255.255.254
  • An easy way to self-reference (ping 127.0.0.1)
• Reserved addresses
  
  • Set aside for future use or testing
  • 240.0.0.1 through 254.255.255.254
• Virtual IP addresses (VIP)
  
  • Not associated with a physical network adapter
  • Virtual machine, internal router address