[Kea-users] ignoring DHCP-Requests which have set the BROADCAST flag

Francis Dupont fdupont at isc.org
Wed Jun 3 21:14:59 UTC 2020

Stefan Berger writes:
> is it possible to drop or ignore DHCP-Requests from clients which have set th
> e BROADCAST-Flag? (0x8000)

=> I can see at least two easy ways: use a firewall (the flag is at a fixed
offset so trivial to find) or write a hook for Kea (install it at the
pkt4_receive callout point and return DROP when the query4->getFlags()
has FLAG_BROADCAST_MASK set). As the broadcast flag has a function
in the protocol perhaps it is possible to tweak the configuration
so they failed to be served (e.g. responses do not reach them) but
a direct way is more reliable.


Francis Dupont <fdupont at isc.org>

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