Introduction
This document describes the procedure to reconfigure the Network Access Device (NAD) entry in ISE which is either modified or removed from ISE.
Background Information
There could be multiple scenarios where the NAD entry for a Network Device (which is managed by Catalyst Center) is removed/deleted from ISE(due to manual error some other cause) and now all the device authetication fails as there is no NAD entry in ISE.
Problem
The problem in the aforementioned scenarios is that there is no pre-defined option in Catalyst Center to create the NAD entry directly once the Network Device is assigned the site and NAD entry is created first time, resulting in users having to configure/modify the NAD entry in ISE manually which can be time consuming and prone to error.
This document describes the procedure/steps to reconfigure the NAD (Network Access Device) entry for any Network Device in ISE which is either modified or removed from ISE NAD. This procedure is applicable for any Network Device which is managed by Catalyst Center.
Solution
To have Catalyst Center configure the NAD entry in ISE, we basically need to change the management IP address of the device (to any dummy IP) which is backend triggers the NAD entry creation workflow. ( make sure that there is no existing NAD entry present in ISE for the same device name).
This procedure is applicable for any Network Device which is managed by Catalyst Center. The NAD entry is created with original IP (as the workflow triggers before the change in management IP address).
in this example device with name : pod7-9400 . dr . com is used.

However, there is no NAD entry in ISE for the same device :
NAD Entry does not exists in ISE for the Network Device
Change the management IP address in Catalyst Center to dummy IP which triggers the workflow to create the NAD entry in ISE. When you change the Management IP address it moves the device Managebility to Syncing state and ISE NAD entry must be created.
Changing the Management IP address for the Network Device in Catalyst Center to Dummy IP
Device goes in Syncing State, as the dummy IP would be unreachable, eventually the device goes into unreachable state.
Network Device goes into Syncing State
Network Device becomes Unreachable and UnManaged as Management Ip address is dummy IP and not reachable from Catalyst Center
NAD Entry got created:
NAD Entry ISE for a Network Device
After this is created, we can change the management Ip address back to its original IP.
Changing the Management Ip address back to its Original IP
After updating the management IP address to its original IP address, the device goes into "syncing" state and becomes "Managed".