Proxy client configuration fro ISA Array

  • From: "John C. Shepard" <jshepard@xxxxxxxxxxx>
  • To: <isalist@xxxxxxxxxxxxx>
  • Date: Fri, 19 Apr 2002 09:37:09 -0700

Hello folks.
 
We have 2 ISA servers, members of an array (ISA1-10.0.0.1,
ISA2-10.0.0.2, Array1)
For this example, DNS forward lookup Zone is domain.local
In this zone the following records:
   CNAME: WPAD pointing to array1.domain.local
   A record: array1 pointing to 10.0.0.1
   A record: array1 pointing to 10.0.0.2
 
Two questions...
How to configure our Proxy Clients to take advantage of the array for
fault tolerance, if one ISA server was to fail?
What is the easiest way to configure IE6 as proxy client if we don't
want to use the Firewall Client?
 
Regarding question#1:
The array itself is not addressable by a single IP address unless we do
NLB or something of that sort. We are already doing NLB on the external
NICs (thanks to Tom's great article on NLB) so that is not an option. I
read in several places that fault tolerance can be achieved with WPAD
and DNS. What am I missing? In the above example DNS, at best, will
resolve in round-robin fashion. That means only about 50% of client
requests will be serviced if one server was to fail. Is there some
built-in feature in WPAD and the autoconfig script that magically finds
the viable ISA server?
 
Regarding question#2:
What we are trying to avoid is, having to configure every single IE with
proxy settings. There is got to be a way for the proxy settings to
propagate down to all the clients. Is that where DHCP comes in? Will a
WPAD DHCP Scope Option propagate down to all the clients' IE Internet
Options?
 
Seems like it should be a no brainer but I'm stuck with these 2
things....
 
John

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