Microsoft: Active Directory health/post Checks for Domain Controllers including replication error

We have normal scenario such as DC got crashed or rebooted and many other cause to have the common steps that we can do health checks on domain controllers.  we normally do AdminPrep which is not a right thing as of now.I”ll post some health check stuff here.  which you guys can go through and come back if what else can be done on this DC if got crashed or rebooted state.

The Event Viewer is always a must.  I look at all the logs before and after the update to the domain controller looking for abnormal events.  With the pre-check I usually go back a month of logs to get more historical data. I then run through a couple command line utilities.  One thing I always do is pipe my commands out to a text document.  This just makes it easier for me to read and also search for failed events.

Dcdiag.exe /v >> c:temp_dcdiag.txt
This is a must and will always tell you if there is trouble with your DCs and/or services associated with it

Netdiag.exe /v >> c:temp_Netdiag.txtThis will let me know if there are issues with the networking components on the DC.  This along with the post test also is a quick easy way to ensure the patch I just installed is really installed (just check the top of the log)

Netsh dhcp show server >> c:temp_dhcp.txtSome may not do this but I”ve felt the pain of a DHCP server somehow not being authorized after a patch.  This allows me verify the server count and names.

Repadmin /showreps >> c:temp_rep_.txtThis shows all my replication and if it was successful or not.  Just be aware that Global Catalogs will have more info here than a normal domain controller.

repadmin /replsum /errorsonly >> c:temp_rep_err.txtThis is the one that always takes forever but will let you know who you are having issues replicating with.

Hopefully this helps you when you troubleshoot your domain controllers but by no way is this an all encompassing list of things to do.  These are the some standard steps we all wil take but I would love to hear what you all do as well. Thanks