Grommit Posted February 14, 2007 Posted February 14, 2007 Hi Bit confused here.. I have 1 Domain with 3 DC's.. two in the Curricilum Area and One in the Admin area.. I took the primary DC with the FMSO roles on down to do some work and the users could not log on (said domain unavailable) I thought the reason of having additional DC's was so if one failed the others would authenticate and the users could get to their files on the file server... Why did this not work ?
DMcCoy Posted February 14, 2007 Posted February 14, 2007 Do the other DCs also provide DNS/DHCP to the clients? You need to make sure your clients have a secondary DNS server set to another DC if you want it to work.
Grommit Posted February 14, 2007 Author Posted February 14, 2007 Do the other DCs also provide DNS/DHCP to the clients? You need to make sure your clients have a secondary DNS server set to another DC if you want it to work. They all have DNS, AD, Print and File... but only the Main DC has DHCP services installed How do i set all the clients to point to the secondary DNS server.. in the Primary DC's DHCP settings ?
ajbritton Posted February 14, 2007 Posted February 14, 2007 Which servers are clients pointing to for DNS?
Grommit Posted February 14, 2007 Author Posted February 14, 2007 To the the 2 Main DC's 192.168.1.1 and 192.168.1.4 My DC's are 192.168.1.1 FMSO Roles.. AD, File, Print, DNS, DHCP 192.168.1.4 AD, File, DNS 192.168.1.12 AD, File, DNS How do i set the workstations to have a secondary DNS server ?
DMcCoy Posted February 14, 2007 Posted February 14, 2007 You can add the second dns server to the dhcp settings, the clients will need to obtain an ip still if they are dhcp, I have a 50/50 spit dhcp, each taking a different range. Its a pain adding the exclusions, but if you already have lots the settings can be exported.
Grommit Posted February 15, 2007 Author Posted February 15, 2007 are you saying that if I add the secondary DNS server to the workstations the wokstations will be able to log on on even tho the primary DC is down ?
Dos_Box Posted February 15, 2007 Posted February 15, 2007 Yes. That is the point of having more than one DNS server in an AD enviroment. Each server is redundent from the other and simply share vital information (DNS mapping, AD info etc) to enable each other to stay up to date sould one suddenly go down.
GrumbleDook Posted February 15, 2007 Posted February 15, 2007 Another reason why DCs should just be that ... DCs ... so that if they one goes down you don't lose other services like printing, file serving, application serving, websites, proxies, etc ... But in schools the lack of funds often mean that the beefy server you bought has to do so many things.
Grommit Posted February 15, 2007 Author Posted February 15, 2007 Another reason why DCs should just be that ... DCs ... so that if they one goes down you don't lose other services like printing, file serving, application serving, websites, proxies, etc ... But in schools the lack of funds often mean that the beefy server you bought has to do so many things. I agree GD... we have a Proliant Beast that was bought to do everything.
Grommit Posted February 19, 2007 Author Posted February 19, 2007 Yes. That is the point of having more than one DNS server in an AD enviroment. Each server is redundent from the other and simply share vital information (DNS mapping, AD info etc) to enable each other to stay up to date sould one suddenly go down. Just looked at the DHCP settings and the primary DNS server and secondary DNS servers are listed So what could the other reason that users cannot logon when the Primary DC is down ? and the sceondary and 3rd DC's are up.. Says Domain unavailable " :-(
Stese Posted February 19, 2007 Posted February 19, 2007 Question... even though you have set the DNS addresses correctly, if the PDC is down, where are your clients getting IP Addresses from?
Grommit Posted February 19, 2007 Author Posted February 19, 2007 Question... even though you have set the DNS addresses correctly, if the PDC is down, where are your clients getting IP Addresses from? Wouldn't they already have an ip from the Primary DC DHCP lease ?
Gatt Posted February 19, 2007 Posted February 19, 2007 Yep for as long as that lease is active if a client's lease expires whilst the PDC is down then it will need a new DHCP address and will fail returning in an APIPA (169.254.0.1 - 169.154.255.254) and will not let anyone onto the domain. Hope you ghave long DHCP leases and refreshed them all before the PDC was taken down
Jon Posted February 20, 2007 Posted February 20, 2007 In an Active Directory domain all domain controllers are equal...However some are more equal than others. The first DC in a domain will take on the roll of Global Catalog server. If you don't have a global Catalog server available you cannot log on...
srochford Posted February 20, 2007 Posted February 20, 2007 The global catalog thing often bites people. A GC holds a subset of the data held in active directory; not all DCs are GCs because in a multi-domain environment this adds a lot to network traffic etc. If you have a single domain forest then there's no reason not to make all DCs into GCs. Even if you are running 2 domains in a forest - eg staff and student - then the chances are that they are relatively small (ie not millions of accounts) so if you just always make a DC a GC then you never hit problems with no GC server being available.
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