E2K / Mixed Mode / Clients hang

  • From: Christian.Schramm@xxxxxxx
  • To: exchangelist@xxxxxxxxxxxxx
  • Date: Thu, 5 Feb 2004 18:16:54 +0100

Dear list,


After migrating some test users to the exchange 2000 server, we are
discovering some issues. 


Config as followed:


-          Mixed mode site (one 5.5 server / one exchange 2000 server)

-          Site integrated in organization with several different sites
(some also in mixed mode, some plain 5.5)

-          Between some the sites are packet filters / firewalls which don`t
let unknown traffic pass through


The issues we discovered are:


-          Outlook clients with E2K-mailboxes often hang on startup or while
trying to delete an unread read-notification (?)

-          While hanging we are discovering the clients want to contact
several exchange 5.5 servers in different sites --> running against firewall
--> timeout --> outlook freezes

-          The target ports are 135, 139 (netbios) and 445 (Microsoft-ds)

-          Clients with mailboxes on the old 5.5 server do not have these
kind of problems


So my question is, why do the exchange 2000 clients want to talk to so many
5.5 servers? Is it possible to turn this communication off? Since this
behaviour is restricting the usability of the new clients and we don't want
to open these "unsecure" ports on the firewall for all clients, I need a
solution soon.


Any comments and hints are welcome.


Thank you in advance.


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