Macintosh client & Entourage proxy errors

[Ian Robinson]

We recently upgraded an ISA2000 server to ISA2004 as part of a larger
Windows 2000/Exchange 2000 to Windows 2003/Exchange 2003 migration
project.

Everything is fine with the new infrastructure apart from some issues
with 3 Macintosh clients and some PDA clients that sync to the Exchange
2003 servers.

The 3 Macintosh clients are running MacOS X 10.3.x (one is on 10.3.9
with the others on 10.3.7 IIRC). They can browse the Internet fine from
these machines. When accessing an external page for the first time
after starting the browser they are prompted for their ISA proxy login
and password. That's all fine.

However when trying to use Entourage to access the the new Exchange
2003 server (which is running on a cluster node) we an error, when you
try to send or receive mail with the error code -18498 and the text
"Proxy Error: The proxy cannot fulfil the request". One of the machines
can access the Exchange server fine using Outlook 2001 for Macintosh
under Classic.

Also the same three Macintosh machines cannot browse to an internal web
server either via IP address or server name (FQDN or distinguished
name). The machines can ping the web server and can resolve it's name
via NSLOOKUP. But when the browser hits the server we get the proxy
returning the following error:
"Error Code 502 Proxy Error: The Proxy Server Denied the specified URL.
Error 12202."

Al of the Windows based clients can access the internal web server in
question with no problem. Some of these are located in the same office
, and on the same network infrastructure, as the Macintosh clients.

Another possible related error is that some Pocket Pc based hand held
devices that staff use to get remote access to email are also giving
errors. They can connect to the network okay but when they try to sync
mail with Exchange they get a HTTP 407 error that seems to be proxy
related.

This all worked with the previous ISA 2000 server. Anyone seen anything
like this with ISA 2004? Any pointers to a solution?

Ian

 

[Corentin Cras-Méneur]

Al of the Windows based clients can access the internal web server in
question with no problem. Some of these are located in the same office
, and on the same network infrastructure, as the Macintosh clients.

I suspect ti has something to do with the network setup.

I've seen something like that when the Mac were just setup to pull the
data from the DHCP server instead of manually entering the information
(eg: DNS server address, etc).

Corentin

 

[Ian Robinson]

I've seen something like that when the Mac were just setup to pull the
data from the DHCP server instead of manually entering the information
(eg: DNS server address, etc).

So should we make the Macs static IP clients and forget about DHCP on
them?

Ian

 

[mmmmark]

So should we make the Macs static IP clients and forget about DHCP on
them?

Ian

DHCP seemed to clean up its act for me at about 10.3.5. I haven't had any
problems with it since, and have quit assigning manually.

-Mark

 

[Corentin Cras-Méneur]

So should we make the Macs static IP clients and forget about DHCP on
them?

That's not what I meant. I meant dn't let the Mac get the DNS server
address etc from the DHCP server. Manually enter all the extra
parameters you can think of (DNS server address, domain name....) but
let the server assign the IP.

Corentin

 

[Ian Robinson]

That's not what I meant. I meant dn't let the Mac get the DNS server
address etc from the DHCP server. Manually enter all the extra
parameters you can think of (DNS server address, domain name....) but
let the server assign the IP.

Okay. I'll try that.

Ian

 

[Corentin Cras-Méneur]

Okay. I'll try that.

I'll be away for a week or so, so don't be surprised if I don't answer
back immediately ;-)

Corentin