Cisco ISE 2.1 Phone restarting on 802.1x port

[dialloahe]

Hello Team,

I am using Cisco ISE 2.1, the problem is the Phones are a restarting everytime. the Worked fine... we dont know why ISE behaving like that.

[agrissimanis]

There could be many reasons why this happens. What is the make and model of the phones? What are your ISE policies? How does the switchport config look like?

I had the same issue with Alcatel phones randomly rebooting, it turned out that the dot1x setting on the phones had to be manually disabled, otherwise they just kept on trying to authenticate with dot1x and often (not always though) reboot on failure.