AD replication from site to HQ

Question

Hi. I have this settings where the DC from HQ is replicated throughout the sites and we have multiples sites configured. Each site consists of two seperate DC. Eg: DCXX01 & DCXX02. The problem faced is that once we create an user account in DC at this one site, it would not appear at HQ and other sites DC. I have tried repadmin /syncall and repadmin /showrepl. Both showed that the replication is successful. But, when we create an user account on DC at HQ, it appears at all the sites. It's like a one way replication. The HQ DC is using Windows Server 2012 and the sites DC is using Windows Server 2019.

DCA (hq) | DCB (hq) | DCC (site1) | DCD (site1):

DCA / DCB ---> DCC / DCD ✅

DCC / DCD ---> DCA / DCB ❎

Answer 1

I'd check the required ports are flowing between networks.
https://learn.microsoft.com/en-us/troubleshoot/windows-server/identity/config-firewall-for-ad-domains-and-trusts#windows-server-2008-and-later-versions
https://www.microsoft.com/en-us/download/details.aspx?id=24009

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