[Kea-users] Lease affinity of released leases

[Johannes Midgren]

> * Hi Johannes,  One of Kea's built-in classes is the "DROP" class. Packets
> associated with this class are, as the name suggests, dropped. You can test
> for dhcpv4 DHCPRELEASE packets with "test": "pkt4.msgtype == 7" Which gives
> the following:    "client-classes": [        {            "name": "DROP",
>            "test": "pkt4.msgtype == 7"        }    ]    or for dhcpv6
>   "client-classes": [        {            "name": "DROP",
>            "test": "pkt6.msgtype == 8”        }    ]  /Peter *
>

*Hi Peter,*

Oh, this was a very valuable tip - thank you indeed!

I had to try it out before replying and it's just as easy as you imply. I
tested with a few hosts and KEA confirmed in the logs with "EVAL_RESULT
Expression DROP evaluated to 1" whenever a DHCPRELEASE was dropped. When
the host requested an IP address after reboot, it got the same one back
from KEA as it had before shutting down.

For my networks with few clients and lease expiration/reclamation
configured, I see no risk with dropping the release packages, so I'll
simply let this remain in my configuration.

I did read about client classes briefly but never grasped that it could be
used in this fashion. This sure is a powerful feature, so I'm sure I'll
find more uses for it in other cases.

Best wishes,
Johannes
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