I'm attempting a dhcp/dynamic-dns setup for a small network with two subnets and I am experiencing troubles when the same client machine tries to boot from two different partitions/OS's.

Both linux services, dhcpd and named (bind 9.3.1), are running on the same redhat linux server (2.6 kernel). The dual boot client test machine has two partitions; the 1st boots XP, the 2nd boots a RH 2.6 kernel.

The network has two subnets; 172.16.1.0/24 and 192.168.1.0/24. I forget why I did it now, but at some point during troubleshooting I adjusted the upper limit of the 172.16.1.0 scope from 172.16.1.249 down to 172.16.1.99. (Both scopes will/should have a range of x.x.x.10 thru x.x.x.249)

That obviously wasn't the fix, but after various other changes, that *was* the address (172.16.1.99) that dhcpd handed out when things finally started to work as they should.

I was able to swing the ethernet cable from the 172.16.1 VLAN to the 192.168.1 VLAN. Again with success, and dhcpd this time allotted an IP address of 192.168.1.249, as it should. *all was well !*

Both of these successes occurred while the laptop was booted using the XP partition. With 1/2 of a victory under my belt I attempted to boot the test machine using the RH partition.

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This is when my *real* confusion/questions start…

The host name of the test machine is 'delta', weather booting XP or RH

Remembering the change to the 172.16.1 scope I made earlier, I moved the upper limit of the 172.16.1 subnet back to .249, restarted all daemons on the server(s) and brought up the test client this time using the RH partition.

When I re-started the test laptop this time, booting the linux 2.6kernel, plugged into the 172.x.x.x VLAN,
dhcp assigned the test machine an address of 172.16.1.249, the new/reconfigured upper end of the scope verified with 'ifconfig' and the file /var/lib/dncp/dhcpd.leases.

Dhcp handed out a new lease (.249) to the test machine and I am able to ping all hosts by ip address. But the dhcpd or the named daemon (not sure which one) did not touch the dns journal files and now dns is broken for this linux boxes.

As an old school hardware guy I understand dchp as "arp-ish" in nature; one mac address-to-one ip address.

Why does dhcpd assign a different address (172.16.1.249) to the newly booted, but same *physical* box using the same NIC with the same mac address and same host name yet but inform named/Bind?

Even though the upper limit of the scope was changed back to 172.16.1.249, isn't the address of 172.16.1.99 (lease of 7 days) already within that range?

Any input or suggestions would be greatly appreciated

Thank you.

When the XP machine shuts down, it tells the DHCP server "Hey. . .this lease is free. You can give it to someone else."

Now, sometimes it'll renew that address in a new OS, sometimes it won't. It's luck of the draw.

As for Dynamic DNS not working. . .no clue.