There are a lot of articles on this subject, and I tried many of them before posting this, so here's where I am at. We have a multi-site single-domain AD forest. All DCs are running Windows 2003 SP2.
Over the weekend, we had to re-IP our datacenter (where the PDC emulator sits) to bring our address scheme into compliance with the company that just acquired us. Since that time, when I run DCDIAG on the PDC emulator, all tests pass except this one:
Starting test: Advertising
Warning: MASTER is not advertising as a time server.
......................... MASTER failed test Advertising
Here MASTER is the name of the PDC emulator.
What have I done?
I have unregistered and re-registered the w32tm service (after backing up the registry key) so I could start with a clean slate.
Once I had a clean slate, I changed
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W32Time\Parameters\Type to NTP from NTDS5
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W32Time\Config\AnnounceFlags from 10 to 5
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W32Time\TimeProviders\NtpServer\Enabled from 0 to 1
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W32Time\Parameters\NtpServer to ntp0.cornell.edu,0x1
Then I stopped and restarted w32time
To check communication with the external time source, I ran nslookup ntp0.cornell.edu and it returned:
Then I ran w32tm /resync /rediscover
It completed without errors.
I checked the event log and I had a message 37 "The time provider NtpClient is currently receiving valid time data from ntp0.cornell.edu (ntp.m|0x1|192.168.60.11:123->126.96.36.199:123)." and a message 35 "The time service is now synchronizing the system time with the time source ntp0.cornell.edu (ntp.m|0x1|192.168.60.11:123->188.8.131.52:123)."
After doing that, another run of DCDIAG still returns the same message that MASTER is not advertising as a time server. Other DCs are logging event 38 "The time provider NtpClient cannot reach or is currently receiving invalid time data from master.XXXXXX.com (ntp.m|0x0|192.168.63.10:123->192.168.60.11:123)."
I am at a loss... prior to the above set of steps I tried things like NET TIME /SETSNTP:ntp0.cornell.edu... which completed without errors, but I still can't get my PDC emulator to advertise as a time server...