[Kea-users] IP reservation for multiple MAC addresses

Oswald oswald.cornwallis.thake at gmail.com
Thu Sep 3 17:44:08 UTC 2020

Hi Robin,

Not recommended and not tested - but it might work in your situation.

 "Dhcp4": {
   "client-classes": [ {
      "name": "Stack"
   },  ],

   "reservations": [ {
      "client-classes": ["Stack"],
      "hw-address": 00:15:e9:7c:56:8e", }
   "client-classes": ["Stack"],
   "hw-address": 00:15:e9:7c:56:8e"
   } ],

   "subnet4": [ {
       "subnet": ""/24"
       "reservation-mode": "global",
       "pools": [ {
          "pool": ""
          "client-class": "Stack"
   } ],


On 03/09/2020 16:58, Robin Daermann wrote:
> Hi,
> On Tue, Sep 01, 2020 at 09:02:27PM +0200, Marcin Romanowski wrote:
>> No this configuration is still incorrect. From network engineer
>> perspective
>> that configuration assumes that could be one ip address with
>> different mac
>> addresses at the same time. This is a network issue. Don't do that.
> I know that, I'm the network engineer. But there are lots of other
> reasons for duplicate IP addresses, so I would not bother for this
> additional one, given the fact that it is much easier to generate
> duplicate IP addresses when setting them up manually instead of using
> DHCP for it.
> We also have a bunch of switch stacks that need DHCP. They often come up
> with different stack master and therefore different MAC address, so this
> feature would help us a lot. Sure, it's just like a "bug fix" for
> vendors not being able to handle out consistent MAC addresses from their
> switch stacks but unfortunately we have to work with it.
>> If you want to share the same ip address with different devices consider
>> using option 82 and assign addresses based on port.
> We can't do that.
>> you also can make user class with test where you provide your mac
>> addresses
>> as key and assign that class to reserved ip address. I've never do that
>> way, but could work.
> I will test that in the next days.
> Best regards,
> Robin Därmann
> (Network Operation Center RUB)

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