ISE Endpoint abandoned EAP session and started new

[hs08]

Anyone know how to solve error for '5440 Endpoint abandoned EAP session and started new'.

Here my full log and below is my config in access port.

interface GigabitEthernet5/0/1
switchport access vlan 250
switchport mode access
authentication event fail action authorize vlan 118
authentication event no-response action authorize vlan 118
authentication port-control auto
mab
dot1x pae authenticator
spanning-tree portfast
end

[Arne Bier]

It could be that there is a delay in the EAPOL frames getting back from ISE to the endpoint - the thing is, that the endpoint has abandoned the session and started a new one - which means that there is something that has triggered the endpoint to do this.

What type of device is this? 

EAP-TTLS ? Are you sure that your endpoint is using EAP-TTLS, and what is the inner auth method?

Is there a slow WAN link between ISE and the switch?

[Jonatan Jonasson]

With this type of an error, aside from MTU issues, the best debug info is usually the client logs. They often state clearly why it abandoned the session, maybe due to certificate trust issues, and/or misconfig on the client side.

There's also a 802.1X learning path on Cisco-U that could be of interest to you:
https://u.cisco.com/paths/introduction-8021x-operations-cisco-security-professionals-140