When having an old Winsdows 2003 dhcp server, which doesn't understand the dhcp identifier OS'es such as Fedora 29 and Ubuntu 18.04 server sends. Which looks like


RFC 4361 should be the RFC about this new way to identifying hosts.

When I take a CentOS 7 as dhcp server, which should support this, both Fedora and Ubuntu presents the MAC address, which I did not expect, as one has to add

send dhcp-client-identifier = hardware;

to /etc/dhcp/dhclient.conf disable this new method on Fedora and Ubuntu.


Can someone explain if this new method is just "protocol" and therefore something the Linux admin will never see, if the dhcp server supports this?

In order words, will the DHCP reservations still be based on MAC addresses or this new method?

  • This "new" method is more than a decade old. And I'm not sure we can even predict what will happen when you use an obsolete server with modern clients. Remember that that Windows server was supposed to have been decommissioned years ago. – Michael Hampton Nov 9 '18 at 14:36
  • Yes, this is not about the Windows dhcp server. Here I know it doesn't understand it. The question is about when using a modern dhcpd server on CentOS 7. – Sandra Nov 9 '18 at 14:48

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