Microsoft Exchange Clients must be able to resolve the Exchange Server by
name AND IP address ALL of the time. When you key in the initial IP address
during client configuration it immediately resolves that IP to a NetBIOS
name. The client has only used the IP address to discover the NetBIOS name.
This does not mean your client can resolve in both directions (IP to Name
and Name to IP)
Without some type of mapping, be it WINS, DNS, or a hosts file, you will
have problems. Even though during configuration the client was able to
resolve IP to NetBIOS this does not mean it will be able to resolve future
requests for NetBIOS to IP. Your client now has a NetBIOS name in the
configuration with no method to find the IP address of the server until you
enable on of the methods stated earlier.
You can either configure a WINS server with the mapping, create an entry in
the hosts file of each client, create an entry in the lmhosts file on each
client, or create a resolvable DNS entry.
Test you client configuration by pinging X.X.X.X (IP address of Exchange
Server) AND pinging the NetBIOS name.
ping X.X.X.X
ping ExchangeServerName
If both of these methods work then your clients should work. Name to IP and
IP to Name resolution is the key. You must have both. The resolve during
client configuration is misleading. It does not mean all of the necessary
resolution is working for the client.
Exchange and Outlook is something I am very familiar with. If this does not
solve your problem, provide me with some feedback and I am confident we can
get it working.
Jim B.
-----Original Message-----
From: John Hovell [mailto:[EMAIL PROTECTED]]
Sent: Wednesday, August 30, 2000 4:42 PM
To: [EMAIL PROTECTED]; Belanger, Derek
Subject: Re: [FW1] MS Exchange 5.5 to work with Checkpoint 2000
Derek --
Thank you very much for the response. I don't know much about Exchange,
other
than exchange protocol is a nightmare with firewalls. Do you mean this
is
because every time I fill in as my exchange server in the client's
configuration
by it's IP: 123.45.67.89, it immediately changes into NETBIOS-NAME (the
name
that Windows calls this thing)?
That _is_ what's happening, and if I change it back to the IP address, I
can get
at least a username/password logon dialog box, but it fails after this
(default
information store could not be opened). (and the client config goes
back to
specifying the server by NETBIOS-NAME -- and I see nothing more in the
firewall
logs)
This is what made me think WINS, but I'm not even sure how to go about
this for
our size organization (less than 25) with people dialing in remotely via
the
VPN-1.
Any hints/clues how I am supposed to get this working? Thank you very
much.
Cheers,
John
"Belanger, Derek" wrote:
> If both the user name and server name resolve in the "Exchange Server"
> service property sheet within the MAPI client profile, the issue is
not
> likely the firewall.
>
> --Derek
>
> -----Original Message-----
> From: John Hovell [mailto:[EMAIL PROTECTED]]
> Sent: Wednesday, August 30, 2000 12:59 AM
> To: [EMAIL PROTECTED]
> Subject: [FW1] MS Exchange 5.5 to work with
> Checkpoint 2000
>
> Hello all --
>
> I am trying to configure my FW-1 to allow users from
various
> subnets
> (VPN and other local) to access an MS Exchange server
I have
> on a local
> segment.
>
> The Exchange server is running the Exchange protocol
for
> client
> access... So far, I haven't been able to connect
correctly.
>
> FW-1 logs are showing no dropped packets (just a few
on port
> 135
> *accepted* and then nothing else) but the Outlook (97
or
> 2000) fail to
> connect (Error: Outlook cannot open your default mail
> folders -- Would
> you like to open your default file system instead?)
>
> I am thinking it could be one of a couple things:
>
> -- FW-1 is somehow dropping packets I don't know about
>
> -- I need to set up WINS in order for Exchange to
> communicate with hosts
> on other subnets (but I don't think so, because I'm
pretty
> sure people
> can access Exchange right over the Internet if there
is no
> firewall).
>
> -- Something else??
>
> Does anyone have any experience with this kind of
setup with
> Exchange
> 5.5? I am running Checkpoint 4.1 SP2 under Linux.
> Everything else is
> running fine.
>
> Also, I tried disabling the "silent service" drop, but
that
> did not
> improve the situation. For now, my policies Are ANY
ANY ANY
> in both
> directions between subnets.
>
> Thanks,
> John
>
>
>
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