Hi!
These are the commands that I use when I do an AD health check.
Dcdiag /a
Dcdiag /q
Repadmin /showrepl
repadmin /replsum /bysrc /bydest /sort:delta
If the tests showed above fails:
dcdiag /test:replications
dcdiag /test:netlogons
dcdiag /test:dns
dcdiag /test:MachineAccount
dcdiag /s:<DomainControllerName> /test:knowsofroleholders /v
dcdiag /s:<DomainControllerName> /test:fsmocheck
I hope it help you!
Marc