First some general background:

Cisco have a Wireless LAN Controller (WLC) configuration that holds a setting named “DHCP Address Assignment Required" (also known as  “DHCP Required” option). This option allows the end-user to force a client DHCP address request/renew every time they associate to the WLAN before they are allowed to send or receive other traffic to the network, and is targeted to enhance the security policy through extreme strict IP addressees control (for further information look in Cisco's web page)


“DHCP Required” affects the total time for roaming before traffic is allowed to pass again. This does not affects regular windows client reconnections, but may cause issues to time sensitive flows that prefer not to perform DHCP renew until the lease time expires.

When “DHCP Required” is enabled, a DHCP renewal is required when there is a reboot or a reload of the WLAN driver during a AMT healing session. The Cisco's WLC will block any traffic to and from this client until the DHCP renewal completes.


So what is the problem?


In cases where DHCP renewals take too long, 5 seconds or more, (for example in environments with DHCP relay agents) the Wireless AMT TCP connection might disconnect and break the healing session.


What can be recommended to avoid the problem?


So actually Intel recommends just to follow Cisco’s instructions that can be seen in above web page: “In general, it is a good idea not to use this [DHCP required] option if the WLAN has non-Windows clients", and disable this option for Wireless AMT environments.