ISE 2.4 and restart the second ISE server which hasn't been active for

[MonkeyBear007]

We have one primary PAN ISE in 2.4 one blade server is is Admin / Monitor and Second blade has the policy
Don't ask why we are still using 2.4

I want to add the Secondary PAN which hasn't been active over 1 year 
I should just be able connect the secondary ISE Admin/monitor and Policy to the network 
It should auto  see each other and start using Both primary and secondary?
Anything I need to watch out for since they have been disconnect so long?

[Karsten Iwen]

I have no idea how it will behave after that long time. But as a precaution I would reinstall the secondary and add it back to the deployment. Or even better, use this opportunity to build a new deployment based on 3.2 and move to that.

[MonkeyBear007]

it's a budget thing and keep been getting delay and need to restore secondary for now

[Mark Elsen]

   >....Don't ask why we are still using 2.4
  We should actually , because it is an important point 
  You risk new network equipment becoming incompatible with ISE ; or software
  For instance modern 9800 wireless controller with latest software is only validated
  against the current ISE versions (this may start to happen to other equipment which you have too
  or perhaps has already happened)

  >...I want to add the Secondary PAN which hasn't been active over 1 year 
 And we should seriously wonder about that too , because standard ISE  production use then becomes
 not valid

      - There is no way out then trying (which with decent network management , including  ISE should not have happened).
         First scrutinize the boot process of the secondary through a (the)
         console ; check if there are no fatal errors or indicators for that during the boot process
         Once it has booted without problems , check the status of the applications using : show application status ise
        Then look at the primary and check if the secondary has become available , 

 M.

[MonkeyBear007]

it's the way it is here
They should of went with 2.7 before license model change
We are waiting budget for ISE 3.x and we don't use cisco wireless controller and switch to Cisco Merial wireless.
Budget is a big factory

[Mark Elsen]

        >...Budget is a big factory
  - Yeah but a failing and incompatible NAC deployment becomes a collapsing factory....

 M.