The error "the attempt to establish a replication link for the following writable directory partition failed" on a Windows Server 2016 typically indicates issues with Active Directory replication. Here are some steps to help you resolve this problem:


### 1. Check Network Connectivity

Ensure that domain controllers can communicate with each other. Verify there are no network or DNS configuration issues.


- **Ping**: Make sure you can ping between the domain controllers.

- **DNS**: Ensure DNS records are correctly configured and DNS servers are accessible.


### 2. Verify DNS Configuration

DNS is crucial for Active Directory replication. Make sure SRV and A records are properly configured.


- Open the **DNS Manager** console and check the records in the forward and reverse lookup zones.

- Use `nslookup` to verify that domain controllers can resolve each other's names.


### 3. Check Active Directory Services

Ensure that necessary Active Directory services are running on all domain controllers.


- On each domain controller, open **Services** and check that services like **NTDS (Active Directory Domain Services)** and **KDC (Key Distribution Center)** are running.


### 4. Check Active Directory Health

Use the `dcdiag` tool to perform a diagnostic check of Active Directory and verify the health of domain controllers.


```shell

dcdiag /v /c /d /e /s:<DomainControllerName>

```


This will run a series of tests and report any issues found.


### 5. Check Event Logs

Review event logs in the Event Viewer for additional details about the error.


- Open **Event Viewer** > **Windows Logs** > **Directory Service**.

- Look for events related to replication errors (e.g., event IDs 2042, 1311, 1865).


### 6. Force Replication

Use the `repadmin` tool to force replication and check its status.


- To force replication:

  ```shell

  repadmin /syncall /A /e /P /q

  ```


- To check the replication status:

  ```shell

  repadmin /showrepl

  ```


### 7. Verify Active Directory Sites and Services Configuration

Check the **Active Directory Sites and Services** configuration to ensure sites and site links are correctly set up.


- Open **Active Directory Sites and Services**.

- Verify that all domain controllers are in the correct sites and that replication links are properly configured.


### 8. Check Security Policies

Ensure there are no security policies blocking Active Directory replication.


- Review local and group policies on the domain controllers to ensure no restrictions are affecting replication.


### 9. Consult Microsoft Documentation

If the above steps do not resolve the issue, consult Microsoft's official documentation and support forums for more information and specific solutions to your environment.


### Useful Resources

- [Microsoft Documentation - Troubleshooting Active Directory Replication Problems](https://docs.microsoft.com/en-us/troubleshoot/windows-server/identity/troubleshoot-ad-replication)

- [Active Directory Replication Troubleshooting](https://docs.microsoft.com/en-us/windows-server/identity/ad-ds/manage/troubleshoot/troubleshooting-active-directory-replication-problems)


Following these steps should help you identify and resolve the replication issue in your Windows Server 2016 environment.