ISA 2004 Enterprise Array Issue - Node2 can't contact the configuration server - Event ID 21238

Hi All,

need some help with this for one of my colleagues please! :)

We have the following Win 2003 domain based environment:

** ISA 2004 Enterprise Edition running on Windows 2003 set up as an ISA array with 2 members.
** Both members OS installed fine and ISA installed (with both firewall and proxy enabled) and configured ok as per the MS ISA quick install guide.
** Node1 installed as both ISA Configuration Storage Server & ISA array member & Node2 just with ISA as an additional array member.
** Internal LAN and external LAN Nics load balanced as per MS ISA guide
** Both members have adequate resources (processor/RAM/HDD/NICs etc) so no bottlenecks there.

Symptoms:
* Node1 works fine (allows browsing out to internet etc)
* Node2 does not work (ie if we stop firewall service on Node1 we cannot browse to internet via Node2 as would be expected given it is an array member)
* Node 2 can't be administered through the ISA mmc - hour glass's for a while then errors saying can't see the configuration storage server - only clue is logged in application log Event ID: 21238 (see below)

Event ID: 21238
Source: Microsoft ISA Server Control
Category: None
Type: Warning
Computer: Node
(Application Log)

ISA Server cannot connect to the Configuration Storage server nodeA.test.co.uk for one of the following reasons:
- The Configuration Storage server is not available.
- General networking or authentication issues.
- A policy misconfiguration on the array.
For information on resolving these issues, see "Troubleshooting installation and connectivity" in the ISA Server help or http://go.microsoft.com/fwlink/?LinkId=37487.
For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp.

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scratching my head as our config looks ok and I couldn't find anything online anywhere!

any help greatly appreciated!

thanks in advance!

Nick