Graham, that's a fairly common question actually, although usually in the Exchange groups. It still could be considered on topic here for part of that data.
FWIW, it's the dsproxy process that hands out GC's to clients to use. That's because of the legacy restrictions the client brings to the equation (see: http://www.microsoft.com/technet/prodtechnol/exchange/2000/deploy/upgrademig rate/series/planningguide/p_08_tt1.mspx and search for DSProxy)Note that different versions of Outlook will respond differently to this process after the first contact is made an a GC is found. DSProxy picks it's GC's based on a number of criteria such as whether or not the domain it's talking to is domainprepped, how close to the Exchange machine the GC is (network), etc. In multi-domain environments, it's not always a good idea to use the closestGC method (see: http://support.microsoft.com/default.aspx?scid=kb;en-us;Q319206). Rather, using a pre-defined becomes more usable as long as that GC remains operational and up to date. Since that's against what Active Directory can do (multi-master concept) then it becomes a burden that many will gripe about (and rightfully so on that one). For those situations, recreating Exchange 5.5 with Exchange 2003/Active Directory seems to be the best workaround: i.e. creating a set of GC's specifically for Exchange usage. This has the added benefit of dedicating GC's to Exchange (better performance) and putting it under Exchange operational control (environmentally isolated). Some would call that a detriment others a great step forward, but all can agree it's just about a waste of hardware :) The problem is that the client doesn't send any site-awareness information. Since Exchange 2003 can't take us back in time while still having to support legacy clients (else many wouldn't buy the upgrade right?), you need to work with it to your environmental strengths IMHO. Why does it only maintain 10 of each? How many does it need? If 10 aren't available, don't you have bigger problems to worry about? The q article discusses your second question and gives details about the behavior. Like I said, be careful to note the versions and if you're spread out over many sites with a centralized Exchange server, consider the recreation of Exchange 5.5 functionality with regards to directory service. Al -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Graham Turner Sent: Monday, July 12, 2004 8:10 AM To: [EMAIL PROTECTED] Subject: [ActiveDir] outlook / gc client discovery dear all, am a bit nervous posting this on account of going way OT as this post falls quite definitely under Outlook 2002 configuration, but there is obviously relation to AD so here goes ... understanding the mechanisms of GC 'discovery' would it seem be very important to optimal deployment of outlook / exchange especially in remote office scenarios. the default outlook configuration seems to use the "view" of the AD topology in terms of DC's and GC's as is learnt by DSACCESS - and reads this from the server on which the outlook client is homed qu 1. why does it only maintain 10 of each ??? - this is a bit like that odd limitation of 25 DC addresses in the WINS (1C) record - and which 10 does it learn ??? qu 2 seems we can override this default behaviour with a registry value (closest GC) - does this reconfigure outlook to behave like the logon server discovery process and use native DNS lookups ??? hope the mail list can be of help on this one GT List info : http://www.activedir.org/mail_list.htm List FAQ : http://www.activedir.org/list_faq.htm List archive: http://www.mail-archive.com/activedir%40mail.activedir.org/ List info : http://www.activedir.org/mail_list.htm List FAQ : http://www.activedir.org/list_faq.htm List archive: http://www.mail-archive.com/activedir%40mail.activedir.org/
