Hello,<br><br>I wonder if somebody could clarify how DHCP server will behave when somebody tries to exhaust its pool by abusing DHCPDECLINE messages. The manpages for dhcpcd.conf says the following:<br><br>...<br> The declines keyword<br>
<br> allow declines;<br> deny declines;<br> ignore declines;<br><br> The DHCPDECLINE message is used by DHCP clients to indicate that the<br> lease the server has offered is not valid. When the server receives a<br>
DHCPDECLINE for a particular address, it normally abandons that<br> address, assuming that some unauthorized system is using it. <u>Unfortu-<br>
</u> <u>nately, a malicious or buggy client can, using DHCPDECLINE messages,<br>
</u> <u>completely exhaust the DHCP server's allocation pool</u>. The server will<br> reclaim these leases, but while the client is running through the pool,<br> it may cause serious thrashing in the DNS, and it will <u>also cause the<br>
</u> <u>DHCP server to forget old DHCP client address allocations</u>.<br><br> The declines flag tells the DHCP server whether or not to honor DHCPDE-<br> CLINE messages. If it is set to deny or ignore in a particular scope,<br>
the DHCP server will not respond to DHCPDECLINE messages.<br>...<br><br>I don't get the part about trashing DNS. Does this refer to the case when DNS updates are on?<br><br>And the statement about reclaiming these leases, but forgetting old DHCP client allocations... Will DHCP server start throwing away existing leases when the pool get exhausted?<br>
<br><br>Any input and/or reference to the official docs relevant to my question are greatly appreciated.<br><br>Best regards,<br>Alexandre Bezroutchko<br><a href="http://www.gremwell.com">www.gremwell.com</a><br><br>