HP 800 User Manual page 401

The DHCP plug-in is a Microsoft DHCP plug-in that utilizes the Microsoft
DHCP Server Callout Application Programming Interface (API). Installed on
each DHCP server in your network, the plug-in processes or ignores DHCP
packets based on the end-user device Media Access Control (MAC) address.
NAC 800 tests endpoints that request access to the network and either assigns
a quarantined Internet Protocol (IP) address (failed), or adds the MAC address
of the end-user device as an authorized device (allowed) to the Access Control
List (ACL) on the appropriate DHCP server.
The following connection and communication actions apply:
■ If the connection between the DHCP server and the NAC 800 server
is lost and re-established, the existing ACL on the DHCP server is
discarded and NAC 800 re-transmits the entire ACL.
If the DHCP server cannot communicate with NAC 800 at any time,
■
the DHCP server goes in to an allow all or deny all state, depending
on the failopen parameter setting in the config.xml file (true =
allow all, false = deny all).
■ NAC 800 attempts to connect to known DHCP servers on start-up, and
continuously attempts to connect at regular intervals indefinitely.
DHCP Plug-in
Overview
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