Commands to check health of Active Directory

Problem Description : 

Run a health check on Active Directory before making major changes/upgrades/dcpromos to AD

 Resolution : 

Open a command prompt on a DC and type

repadmin /replsummary

Will show you an overview of any failures, and for which DC(s). 

Look for any fails. The "largest delta" represents the time between the last replications.

These write to a file for easier viewing...

Dcdiag.exe /v >> c:temppre_dcdiag.txt

Will tell you if there is trouble with your DCs and/or services associated with it

DCDIAG /a

This tests all domain controllers (/a), you can get more verbose with /v,

Repadmin /showreps >> c:temppre_rep_partners.txt

This shows all replication and if it was successful or not. Global Catalogs will have more info here than a normal domain controller.

Repadmin /showrepl

This will let you know if the last replication attempts where successful. 

NETDOM Query FSMO

This will return the FSMO role holders, which can be used to confirm that the role holders are still online and functioning. 

List Global Catalogs

C:\Users\troys>nslookup

Default Server: eagle.gdn.peachnet.edu

Address: 168.26.240.23

> set type=srv

> _gc._tcp.gdn.peachnet.edu

Server: eagle.gdn.peachnet.edu

Address: 168.26.240.23

_gc._tcp.gdn.peachnet.edu SRV service location:

 priority = 0

 weight = 100

 port = 3268

 svr hostname = dc-gsc2.gdn.peachnet.edu

_gc._tcp.gdn.peachnet.edu SRV service location:

 priority = 0

 weight = 100

 port = 3268

 svr hostname = eagle.gdn.peachnet.edu

_gc._tcp.gdn.peachnet.edu SRV service location:

 priority = 0

 weight = 100

 port = 3268

 svr hostname = pegasus.gdn.peachnet.edu

dc-gsc2.gdn.peachnet.edu internet address = 168.26.240.8

eagle.gdn.peachnet.edu internet address = 168.26.240.23

pegasus.gdn.peachnet.edu internet address = 168.26.240.29

 Revision Date : 10/30/2014