Keepalive between ISE and Switch?

[networker4424]

Hello, 

Is there any keepalive mechanism between the switch and ISE. I need to know if there is a way which can enable the switch to know if ISE server is online and available at any particular time.

The idea is that lets suppose we try to authenticate a client through ISE but for some reason the server is not reachable at that time so we'll put the client in the guest vlan but later if the server is back up again, how would the switch know if its up.

Thanks,

[Marvin Rhoads]

Sure - the method varies by the device OS (IOS, ASA or WLC) but the basics are along these lines...

When you define a RADIUS server (ISE) you can configure a username to be used for periodic testing:

radius server ISE01
 address ipv4 172.20.254.21 auth-port 1812 acct-port 1813
 automate-tester username test-user ignore-acct-port probe-on
 key ISEisC00L

Source: https://community.cisco.com/t5/security-documents/ise-secure-wired-access-prescriptive-deployment-guide/ta-p/3641515#toc-hId--554168365