DHCP Relay Opt 82 including Clients' Mac Addresses

Niall O'Reilly niall.oreilly at ucd.ie
Mon Aug 26 11:28:33 UTC 2019

On 26 Aug 2019, at 0:12, Laupoini Manu wrote:

> My current dhcp server is using option 82 parameters like remote-id, 
> circuit-id but unfortunately these two parameters are not unique 
> values to allow dhcp to assign a fixed IP addresses to my client 
> devices, and wondering if I can use client mac address
> Appreciate any input and examples.

Sorry, no example.

You can use option-82 data to place your devices in a class,
and allow that class in an address pool specification.
You shouldn't need to do anything special to arrange for
distinct IP-address assignments for the different MAC

If, by mischance, more that one of your devices is using
the same client ID (if used, derived from MAC address by
default, but may be configured explicitly, so duplicates
are possible), then you'll need to correct this
misconfiguration on the client side.

Any address pool you use in the way suggested above will
need to have a number of addresses at least as great as
the number of devices which are to be accommodated.

Please accept my apologies if some of the above is obvious.
One trouble with DHCP is that almost everything is obvious
in the sense of being hidden in plain sight. 8-)

Best regards,
Niall O'Reilly

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