Question : Force Replication not working properly

Hi,

In a test environment I've set up yesterday, I have a DC and a another DC in the same subnet I installed recently.
I want to let the main DC replicate with the second DC to get rid of the first DC soon.
The first DC also is a DHCP server and obviously a DNS server.
Both machines are Windows Server 2003 SP1.

I made the second DC a member of the domain, then dcpromoted it, and then installed the DNS service on it but didn't configure it (The DNS servers on both virtual servers are AD-Integrated) .
I tried to force a replication using the Active Directory Sites snap-in's "Replicate Now" option but it didn't work with the following error :

---------------------------
Replicate Now
---------------------------
"The following error occurred during the attempt to synchronize naming context TESTLAB.local from domain controller TESTLAB-DEFAULT to domain controller TESTLAB-DC:
The naming context is in the process of being removed or is not replicated from the specified server."

I left the servers switched on this night and this morning, the DNS server on the second DC was replicated, but Replicate Now still gives the same error.
If that doesn't work, it probably means that something is wrong somewhere and it worries me : any idea ?

Check Typology seems to work fine.

Here is a DCDiag Log (first DC) :

Domain Controller Diagnosis

Performing initial setup:
   Done gathering initial info.

Doing initial required tests
   
   Testing server: Default-First-Site\TESTLAB-DC
      Starting test: Connectivity
         ......................... TESTLAB-DC passed test Connectivity

Doing primary tests
   
   Testing server: Default-First-Site\TESTLAB-DC
      Starting test: Replications
         ......................... TESTLAB-DC passed test Replications
      Starting test: NCSecDesc
         ......................... TESTLAB-DC passed test NCSecDesc
      Starting test: NetLogons
         ......................... TESTLAB-DC passed test NetLogons
      Starting test: Advertising
         ......................... TESTLAB-DC passed test Advertising
      Starting test: KnowsOfRoleHolders
         ......................... TESTLAB-DC passed test KnowsOfRoleHolders
      Starting test: RidManager
         ......................... TESTLAB-DC passed test RidManager
      Starting test: MachineAccount
         ......................... TESTLAB-DC passed test MachineAccount
      Starting test: Services
            RPCLOCATOR Service is stopped on [TESTLAB-DC]
            TrkWks Service is stopped on [TESTLAB-DC]
            TrkSvr Service is stopped on [TESTLAB-DC]
         ......................... TESTLAB-DC failed test Services
      Starting test: ObjectsReplicated
         ......................... TESTLAB-DC passed test ObjectsReplicated
      Starting test: frssysvol
         ......................... TESTLAB-DC passed test frssysvol
      Starting test: kccevent
         An Warning Event occured.  EventID: 0x80000785
            Time Generated: 07/27/2007   09:48:46
            Event String: The attempt to establish a replication link for
         ......................... TESTLAB-DC failed test kccevent
      Starting test: systemlog
         An Error Event occured.  EventID: 0x0000165B
            Time Generated: 07/27/2007   09:15:13
            Event String: The session setup from computer 'VIRTUALXPFR'
         An Error Event occured.  EventID: 0x000016AD
            Time Generated: 07/27/2007   09:17:36
            Event String: The session setup from the computer VIRTUALXPFR
         ......................... TESTLAB-DC failed test systemlog
   
   Running enterprise tests on : TESTLAB.local
      Starting test: Intersite
         ......................... TESTLAB.local passed test Intersite
      Starting test: FsmoCheck
         ......................... TESTLAB.local passed test FsmoCheck


DCDiag on the second DC :

Domain Controller Diagnosis

Performing initial setup:
   Done gathering initial info.

Doing initial required tests

   Testing server: Default-First-Site\TESTLAB-DEFAULT
      Starting test: Connectivity
         ......................... TESTLAB-DEFAULT passed test Connectivity

Doing primary tests

   Testing server: Default-First-Site\TESTLAB-DEFAULT
      Starting test: Replications
         ......................... TESTLAB-DEFAULT passed test Replications
      Starting test: NCSecDesc
         ......................... TESTLAB-DEFAULT passed test NCSecDesc
      Starting test: NetLogons
         ......................... TESTLAB-DEFAULT passed test NetLogons
      Starting test: Advertising
         Warning: DsGetDcName returned information for \\testlab-dc.TESTLAB.loca
l, when we were trying to reach TESTLAB-DEFAULT.
         Server is not responding or is not considered suitable.
         ......................... TESTLAB-DEFAULT failed test Advertising
      Starting test: KnowsOfRoleHolders
         ......................... TESTLAB-DEFAULT passed test KnowsOfRoleHolder
s
      Starting test: RidManager
         ......................... TESTLAB-DEFAULT passed test RidManager
      Starting test: MachineAccount
         ......................... TESTLAB-DEFAULT passed test MachineAccount
      Starting test: Services
            RPCLOCATOR Service is stopped on [TESTLAB-DEFAULT]
            TrkWks Service is stopped on [TESTLAB-DEFAULT]
            TrkSvr Service is stopped on [TESTLAB-DEFAULT]
         ......................... TESTLAB-DEFAULT failed test Services
      Starting test: ObjectsReplicated
         ......................... TESTLAB-DEFAULT passed test ObjectsReplicated

      Starting test: frssysvol
         Error: No record of File Replication System, SYSVOL started.
         The Active Directory may be prevented from starting.
         There are errors after the SYSVOL has been shared.
         The SYSVOL can prevent the AD from starting.
         ......................... TESTLAB-DEFAULT passed test frssysvol
      Starting test: kccevent
         ......................... TESTLAB-DEFAULT passed test kccevent
      Starting test: systemlog
         ......................... TESTLAB-DEFAULT passed test systemlog

   Running enterprise tests on : TESTLAB.local
      Starting test: Intersite
         ......................... TESTLAB.local passed test Intersite
      Starting test: FsmoCheck
         ......................... TESTLAB.local passed test FsmoCheck

Answer : Force Replication not working properly

Sounds like the KCC was re-calculating the replication topology.

Maybe the replication topology on the 2 servers wasn't in sync and the scheduled replication forced the updates.

In theory, all servers within an AD site should recieve all updates withing 1 minute of the change being made to any server on the site. All AD servers should be within 3 hops of any other server on the site, and a change is propogated to neighbouring servers 15 seconds after the change is recieved, so the scheduled replication should have happened within 1 minute anyway.