DHCP
• IPv4 address configuration used to be manual
• IP address, subnet mask, gateway, DNS servers, NTP
servers, etc.
• October 1993 - The bootstrap protocol - BOOTP
• BOOTP didn’t automatically define everything
• Some manual configurations were still required
• BOOTP also didn’t know when an IP address might
be available again
• Dynamic Host Configuration Protocol
• Initially released in 1997, updated through the years
• Provides automatic address / IP configuration for
almost all devices
Turning dynamic into static
• DHCP assigns an IP address from the first available
from a large pool of addresses
• Your IP address will occasionally change
- You may not want your IP address to change
- Server, printer, or personal preference
- Disable DHCP on the device
- Configure the IP address information manually
- Requires additional administration
- Configure an IP reservation on the DHCP server
- Associate a specific MAC address with an IP address
APIPA - Automatic Private IP Addressing
• A link-local address - No forwarding by routers
• IETF has reserved 169.254.0.1 - through
169.254.255.254
• First and last 256 addresses are reserved
• Functional block of 169.254.1.0 through
169.254.254.255