Hi, We are deploying 802.1X in our network and have encountered problem with a type of payment terminal. The problem is that the terminal do not 'speak' to the network after the first initial DHCP request, the terminal waits for incoming packets from a counter to start the payment process. After the idle-time the MAC is flushed from the switch and the port is not authorized any more. To solve this we set 'authentication control-direction in' on the port and use 'ip device tracking' to keep the client on the network, ip device tracking sends an arp request every 30 seconds to clients. Our ISE is sending Radius:Idle-Timeout = 300 and the timer start to count down when the client is authenticated. In Wireshark, I can see that the ARP request is going out and the ARP reply coming back in but this does not update the inactivity timer for the client. So after 5 minutes the port is gone, and there is no way to get the port up again from the network. Traffic from the client brings up the network. This looks like a bug to me, anyone seen this, or a similar behaviour? Running: ISE 1.2p6 IOS 12.2(55)SE6   From Trustsec 1.99 Wired 802.1X Deployment Guide: Tip Enable IP Device Tracking with inactivity timers to keep quiet endpoints connected. When IP Device Tracking is enabled, the switch periodically sends ARP probes to endpoints in the IP Device Tracking table (which is initially populated by DHCP requests or ARP from the end point). As long as the endpoint is connected and responds to these probes, the inactivity timer is not triggered and the endpoint is not inadvertently removed from the network.   From CLI output SW03#sh auth sessions int fa0/4             Interface:  FastEthernet0/4           MAC Address:  xxxx.xxxx.5289            IP Address:  10.10.10.64             User-Name:  XX-XX-XX-XX-52-89                Status:  Authz Success                Domain:  DATA        Oper host mode:  multi-auth      Oper control dir:  both         Authorized By:  Authentication Server            Vlan Group:  N/A       Session timeout:  N/A          Idle timeout:  300s (server), Remaining: 2s     Common Session ID:  0A17BD07000000A925152A7B       Acct Session ID:  0x00000458                Handle:  0x090000A9 Runnable methods list:        Method   State        dot1x    Failed over        mab      Authc Success SW03# SW03# SW03# SW03#sh auth sessions int fa0/4             Interface:  FastEthernet0/4           MAC Address:  Unknown            IP Address:  Unknown                Status:  Running                Domain:  UNKNOWN        Oper host mode:  multi-auth      Oper control dir:  both       Session timeout:  N/A          Idle timeout:  N/A     Common Session ID:  0A17BD07000000AA251A0019       Acct Session ID:  0x00000462                Handle:  0x800000AA Runnable methods list:        Method   State        dot1x    Running        mab      Not run               ... View more