DHCP Details You Didn’t Know

If you’ve been a networking engineer (or a sysadmin) for a few years, you must be pretty familiar with DHCP and might think you know everything there is to know about this venerable protocol. So did I… until I read the article by Chris Marget in which he answers two interesting questions:

  • How does the DHCP server (or relay) send DHCP offer to the client that doesn’t have an IP address (and doesn’t respond to ARP)?
  • How does the DHCP client receive the DHCP responses if it doesn’t have an IP address?

3 comments:

  1. Fine subject but fatally flawed by the lack of accuracy in the early article.

    Sometimes I wish I could speak and someone would listen.

  2. First - thanks for your network work for all that time.

    Let me ask again about DHCP with static binding on IOS router.
    I have origin file for the dhcp pool and I badly want to have same static IP addresses for every host no matter what we boot: windows, linux or PXE. Do You have any solution for this? How to force an IOS to treat hw address as client-id when no client-id is passed by the requesting machine?
    Replies
    1. If the question is "I cannot define two entries with the same IP address, is there a way to do it", the answer is "no idea" :(
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