Broadcast NAK problem.

Steve Lancaster stevelan at
Fri Mar 12 01:35:08 UTC 2010

We have run into an interesting problem.

We are currently running 2 dhcp servers on the same net. One is configured
to support hosts on the net, and one is configured to received relayed
requests from other nets.

The dhcp server providing responses to the relayed nets has no entries
which would allow it to issue addresses on the net it's listening on. It
only supports hosts on the nets that were sent by relay agents.

Periodically, the remote net server  will receive a request for an ip
address relayed by one of the clients on the remote network, which is
for an address not valid for the remote network. The dhcp server will
issue a broadcast NAK, even though it's been configured as "not authoratative"
at the top level and in each network stanza for it's real interfaces.

Now.. I would have thought, that, with the interface marked as "not 
authoratative", that the server would never issue a broadcast nak.

When the server issues the broadcast nak, a large number of our Solaris
10 hosts, on the local net, hear the broadcast NAK and all issue a
DHCPDISCOVER.. the real server for that net, hears the DISCOVER and
issues addresses for the Solaris 10 hosts, they then pick up their OLD
addresses, and it's off to the races again. However, they have gone
deaf during the rebind.

Is there a way to keep the "remote" server from issuing broadcast
NAKs? (Ignore booting only works in the host context, apparently.)

Baring being able to keep the server from sending the NAK's, is there a
way to keep the Solaris 10 client from responding to them?


Steve Lancaster
Sr. Systems Admin.
Xerox- Wilsonville

More information about the dhcp-users mailing list