I personally like to call that COST instead of priority. It is just a definition but in my opinion a higher priority is a lower value and is one of the first on the list... A SRV RR with a higher priority value makes sure that value will be used only when SRV RR with lower priority values are not available. Concerning the DSPROXY/DSACCESS stuff... To read about the discovery process of DCs/GCs by Exchange see: http://www.microsoft.com/downloads/details.aspx?FamilyID=c976433f-f979-4745-b7a6-9d8446ef6409&DisplayLang=en Search for "How DSAccess Discovers the Active Directory Topology" In that same paragraph you will also find
ยท DNS priority and weight Each domain controller and global catalog server has a Service (SRV) resource record, which contains both a priority value and a weight value. The administrator preassigns these values to reflect how servers should be load balanced. DSAccess uses only the weight value to determine which server the client should prefer; therefore, administrators can use the priority value to control Active Directory load generated by logons, and the weight value to control Active Directory load generated by Exchange. A higher weight results in a higher probability that DSAccess will choose a server. DSAccess treats a weight of 0 the same it treats a weight of 1. If DSAccess cannot read the weight, it uses a default weight of 100. While Windows clients use DNS to locate DCs/GCs, Exchange uses the AD topology to locate them by using LDAP queries. So no matter what priority you define or even if you configure the DC/GC to not register domain-wide/site-wide SRV RRs it will find and use the DC/GC because it queries AD for a list. I have seen this happen because I remember a migration assignment I did, where I configured a DC/GC for migration purposes only and configured it NOT to register domain-wide/site-wide SRV RRs (only the replication record was registered). One day I was talking with a collegue about how you can see in OL2003 which GC you are using (for those interested: hold CTRL key down and right click on the outlook icon in the system tray and select connection status - if you start outlook and check the connectin status immediately you will see it trying to connect). So I showed him that and suddendly I saw the "migration DC/GC" - which did not register the domain-wide/site-wide SRV RRs (and I checked!) - was being used. Looking what is said above Exchange was not able to read the weight of the migration DC/GC because the SRV RRs were not registered. So it thought... "who cares lets use it though and I will assign it a weight value of 100" I may be missing something but I don't understand why exchange does not use DNS to locate DC/GCs (at least for DSPROXY/DSACCESS when clients need one) like WIndows clients do for logon/authentication purposes. When I read the documentation I interpret it as I wrote it here. So if I have interpret it wrong please tell me so. The only way I can see which DCs/GCs Exchange uses is to hardcode them or to create an Exchange Site with DCs/GCs that are only used by Exchange. With that Exchange creates an in-site list, but it also creates an out-site list to be used when the DCs/GCs on the in-site list are not available for some reason. Concerning your question/remark... >> I have a new DC that I need to make a GC to avoid an NTDS 1419 error on one >> my other DCs (see below) but I don't want any clients to query it. You don't want clients to query what GC? The new GC or the GC with the IM (I assume the latter one). Concerning the IM FSMO role and the GC role look at it from the domain perspective. If all DCs in a domain are GC then it does not matter the IM of that domain is on a GC. You don't have any other choice though. If you at least have one DC in a domain then do not put the IM of that same domain on a GC. For more info on this read: MS-KBQ248047_Phantoms, Tombstones and the Infrastructure Master Cheers, Jorge ________________________________ From: [EMAIL PROTECTED] on behalf of Thommes, Michael M. Sent: Sat 9/24/2005 12:32 AM To: [email protected] Subject: RE: [ActiveDir] global catalog discovery / Outlook XP All this GC talk makes me want to ask the following question - what is the relationship between a non-zero priority value put on a GC SRV record and the output from a "getGClist" call? I have a new DC that I need to make a GC to avoid an NTDS 1419 error on one my other DCs (see below) but I don't want any clients to query it. Will the non-zero Priority value be enough? This DC is both a Global Catalog and the Infrastructure Update master. These two roles are incompatible. If another machine exists in the domain, it should be made the Infrastructure Update master. The machine CN=NTDS Settings,CN=Server4,CN=Servers,CN=West,CN=Sites,CN=Configuration,DC=PRODOM,DC=com is a good candidate for this role. If all domain controllers in this domain are Global Catalogs, then there are no Infrastructure Update tasks to complete, and this message may be ignored. TIA, Mike Thommes ________________________________ From: [EMAIL PROTECTED] on behalf of joe Sent: Fri 9/23/2005 11:07 AM To: [email protected] Subject: RE: [ActiveDir] global catalog discovery / Outlook XP If outlook is configured to use nearest GC I believe it simply falls back to whatever the OS says to use. Check to see if nltest /dsgetdc:forestrootdomain /gc matches up with the Exchange server you use for AB/NSPI ops from outlook. Obviously you could start a network sniffer and see what happens when outlook fires up as well. joe -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Graham Turner Sent: Friday, September 23, 2005 11:05 AM To: [email protected] Subject: [ActiveDir] global catalog discovery / Outlook XP Dear all, i have been away from the list for absolutely ages but i need to go over an issue of GC discovery with Outlook XP that need some help on. this may be regarded as OT to this list, but have posted on an MS Outlook newsgroup site with nothing back so i hope this post to be in order. i recall what ended up as a trilogy many months ago on a similar topic but need to get fairly specific information on the mechanisms used by Outlook XP to locate a GC server. there was much discussion on the configuration of Outlook to use local GC discovery (by way of the CLOSESTGC reg value) but on the basis of this configuration can anyone elaborate on the mechanism that Outlook configured as such uses to locate a GC. as i understand the MS documentation, this registry value disables the 'referral' that the client gets (presumably from DSACCESS / DSPROXY). as such it must then have its own mechanism - THIS IS WHAT WE ARE INTERESTED IN - we have attempted loading the SRV RR's (ldapsrvpriority) so the discovery process is loaded towards a particular GC, but this does not seem to prevail as always assistances gladly received. GT List info : http://www.activedir.org/List.aspx List FAQ : http://www.activedir.org/ListFAQ.aspx List archive: http://www.mail-archive.com/activedir%40mail.activedir.org/ List info : http://www.activedir.org/List.aspx List FAQ : http://www.activedir.org/ListFAQ.aspx List archive: http://www.mail-archive.com/activedir%40mail.activedir.org/ List info : http://www.activedir.org/List.aspx List FAQ : http://www.activedir.org/ListFAQ.aspx List archive: http://www.mail-archive.com/activedir%40mail.activedir.org/ This e-mail and any attachment is for authorised use by the intended recipient(s) only. It may contain proprietary material, confidential information and/or be subject to legal privilege. It should not be copied, disclosed to, retained or used by, any other party. If you are not an intended recipient then please promptly delete this e-mail and any attachment and all copies and inform the sender. Thank you.
<<winmail.dat>>
