Hi ,
suppose that i have a dc and adc and both of them got crasesd due to a sudden disaster, now what is saved in my network to take the place of the AD Server is the child domain controller, So what i want to ask you all  finally is, Will all the users be authenticated or provided all the service as continued with the crased Ad server itself by our child domain controller or not?

Hi

 Do you have any backup of your DC\ADC?f yes first try to recover DC.And also if dont any backup,be quickly seize fsmo roles to your avaible DC.

clients always need Fsmo role holder,and you have to recover or seize fsmo as soon as possible.If you can't recover these fsmo roles,client will not logon,join etc soon.

Follow this article to seize fsmo roles;

https://technet.microsoft.com/en-us/library/cc816779(v=ws.10).aspx

Hi

 Do you have any backup of your DC\ADC?f yes first try to recover DC.And also if dont any backup,be quickly seize fsmo roles to your avaible DC.

clients always need Fsmo role holder,and you have to recover or seize fsmo as soon as possible.If you can't recover these fsmo roles,client will not logon,join etc soon.

Follow this article to seize fsmo roles;

https://technet.microsoft.com/en-us/library/cc816779(v=ws.10).aspx

• Marked as answer by Jitendra Kushwaha 2 hours 8 minutes ago

Hello,

to understand you scenario correct.

You have one domain.com with 2 DCs and child.domain.com with one DC? And now both DCs on domain.com crash and the users from domain.com should be able to work?

For AD backup/restore the minimum required is the so called system state backup from at least one DC in domain.com and child.domain.com.

Therefore use the following articles to get the backup correct prepared:

https://technet.microsoft.com/en-us/library/cc753359%28WS.10%29.aspx?f=255&MSPPError=-2147217396

And here about the worst case scenario with forest recovery:

https://technet.microsoft.com/en-us/library/planning-active-directory-forest-recovery(v=ws.10).aspx

http://blogs.technet.com/b/instan/archive/2008/11/07/dude-where-s-my-forest-root.aspx

AD Disaster recovery site:

http://blogs.technet.com/b/isrpfeplat/archive/2011/12/01/disaster-recovery-site-and-active-directory-part-1.aspx

Thank you so much for your replies, It solved my problems.