Computers having issue reauthenticating

Question

I am having issues with NPS when computers are trying to re-authenticate. Before diving into my issue I'll post my setup. 
Workstations are connected to two different switches that have 802.1x enabled by port. 
I have two Server 2012 domain controllers with NPS role installed. One switch is an Extreme Networks x450a-48T and the other is a x150-48T. Both are running ExtremeXOS version 12.6.3.2.
The issue I am having is that according to the switch, it is having issues talking to my NPS servers. If this happens when a computer is trying to re-authenticate, the authentication fails disconnecting them from the network for either a few seconds or a
couple of minutes. Looking at the time stamp in the logs between the NPS servers and the switch, the errors are within seconds of each other so I cannot tell which one was actually first.
On the server, I get this in the event viewer (identifiable information changed):
Time: 4/22/2014 10:50:37 AMNetwork Policy Server discarded the request for a user.
Contact the Network Policy Server administrator for more information.
User:
Security ID: domain\computername$
Account Name: host/computername.domain.local
Account Domain: domain
Fully Qualified Account Name: domain\computername$
Client Machine:
Security ID: NULL SID
Account Name: -
Fully Qualified Account Name: -
OS-Version: -
Called Station Identifier: -
Calling Station Identifier: <mac address>
NAS:
NAS IPv4 Address: <switch ip>
NAS IPv6 Address: -
NAS Identifier: -
NAS Port-Type: Ethernet
NAS Port: 1015
RADIUS Client:
Client Friendly Name: <switch name>
Client IP Address: <switch ip>
Authentication Details:
Connection Request Policy Name: wired
Network Policy Name: user-office port-based
Authentication Provider: Windows
Authentication Server: NPS1.domain.local
Authentication Type: EAP
EAP Type: -
Account Session Identifier: -
Reason Code: 1
Reason: An internal error occurred. Check the system event log for additional information.
And then when I look at the switch, it has: 
04/22/2014 11:52:02.72 <Info:nl.ClientAuthenticated> Network Login 802.1x user host/computername.domain.local logged in MAC <mac address> port 15 VLAN(s) "user-office", authentication Radius
04/22/2014 11:50:46.58 <Info:nl.ClientReAuth> Network Login user host/computername.domain.local unauthenticated as reauthentication failed, Mac <mac address> port 15 VLAN(s) "user-office"
04/22/2014 11:50:46.57 <Warn:AAA.RADIUS.noRespForDot1xReq> No response from RADIUS server (NPS1 address) for 802.1x request sent from switch.
04/22/2014 11:50:46.57 <Warn:AAA.RADIUS.serverSwitch> Switch to server (NPS2 address)
04/22/2014 11:50:43.56 <Warn:AAA.RADIUS.resendPkt> Resend packet to Authentication Server address (NPS1 address) current packet count is 2
04/22/2014 11:50:40.56 <Warn:AAA.RADIUS.resendPkt> Resend packet to Authentication Server address (NPS1 address) current packet count is 1
I see that the NPS server says the reason code is 1 which means it was an internal error which leads me to believe that the switch cannot contact the NPS server during the time when the server is having an error. I have found the logging failures can lead
to not allowing a client to authenticate but I have logging enabled locally only and within the logging settings, I have "If logging fails, discard connection requests." so even if it was a logging failure, that should not prevent the client from
authenticating.
Any guidance as to what is causing this problem for me and how to fix it?

Answer 1

Hi,
First, troubleshoot the issue by following article.
Access Request Was Discarded
http://technet.microsoft.com/en-us/library/dd348465.aspx
Since error code 1 indicates NPS server error, please verify the configuration:
Configure a Wireless Access Point as an NPS RADIUS Client
http://technet.microsoft.com/en-us/library/dd283005(WS.10).aspx
NPS RADIUS Client
http://technet.microsoft.com/en-us/library/cc735367(v=ws.10).aspx
Checklist: Configure NPS for Secure Wireless Access
http://technet.microsoft.com/en-us/library/cc771696.aspx
802.1X Authenticated Wireless Deployment Guide
http://technet.microsoft.com/en-us/library/dd283093(v=ws.10).aspx
Hope this helps.