DHCP process

Discover

• The device sends a DHCP Discover message using UDP (because it does not have an IP).
  • It’s a broadcast connection that the router ignores (since no IP) but is accepted by the DHCP server.
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Offer

• Since the DHCP server accepts the message from the device, it sends a message (offer via UDP /67) with a potential IP.
  • No way to unicast yet, it’s still a broadcast.
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• The device receives the message from the DHCP server with the IP.

Request

• The device asks the server whether the IP provided by the DHCP server is correct.
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Acknowledgment

• The DHCP server sends a broadcast message to all.
  • The device then configures itself with the IP that was originally sent in the offer and acknowledges.
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DHCP relay