Hi Neil In you domain DNS zone you will see a list of the sites in the _SITES folder. Inside that are the site names and an _tcp folder. This contains the SRV records that are registered for that site. Once a client is site aware (after first logon) my understanding is this. 1) The client queries DNS for a list of DCs in its site. It will then try them in a random order. If nothing is returned, or this fails... 2) The client will query DNS for a list of DCs in the domain. It will then try them in a random order with (I believe) 100ms time out for each before contacting the next.
Gil Kirkpatrick wrote a very good article on controlling this topology with SRV record priorities (ie.lower records are provided first and when they time out remaining records are provided), and on setting manual site coverage. http://www.windowsitpro.com/Windows/Article/ArticleID/37935/37935.html We have used this somewhat, setting the SRV record value for all DCs to 16, except for our hubsite (left at the default value of 0) for the domain. In our scenario the client will 1) Check the site, if there is nothing. 2) Check the hubsite, if they both time out 3) Check every other DC in the domain. Hope this helps; James R. Day Active Directory Core Team Office of the Chief Information Officer National Park Service (202) 354-1464 (direct) (202) 371-1549 (fax) [EMAIL PROTECTED] |---------+----------------------------------> | | "Ruston, Neil" | | | <[EMAIL PROTECTED]> | | | Sent by: | | | [EMAIL PROTECTED]| | | tivedir.org | | | | | | | | | 04/07/2005 03:07 PM CET| | | Please respond to | | | ActiveDir | |---------+----------------------------------> >------------------------------------------------------------------------------------------------------------------------------| | | | To: ActiveDir@mail.activedir.org | | cc: (bcc: James Day/Contractor/NPS) | | Subject: [ActiveDir] DC location queries | >------------------------------------------------------------------------------------------------------------------------------| I would like to ask for confirmation relating to the below scenarios and DC location: 1. Client in site with no DCs installed Client receives list of DCs which have registered SRV records on behalf of that site 2. Client in site with a DC but that DC is unavailable Client requests list of DCs registered at the domain level 3. Client in unknown site Client receives list of DCs associated with the defaultFirstNameSite We have only hub sites register as per point 2 and the default site has been renamed. How do I determine which site has assumed the role of the default site? Thanks, neil ============================================================================== This message is for the sole use of the intended recipient. If you received this message in error please delete it and notify us. If this message was misdirected, CSFB does not waive any confidentiality or privilege. CSFB retains and monitors electronic communications sent through its network. Instructions transmitted over this system are not binding on CSFB until they are confirmed by us. Message transmission is not guaranteed to be secure. ============================================================================== 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/
