Could not start the Distribution Server in the specified port. You will see an error as "Unable to start DS Server" in the SoM page of the web Console.
This error will occur if the HTTP/HTTPS port of the Distribution Server is occupied by some other application. The same error will occur on the both the cases, viz.
You can resolve this issue as follows:
Check and Free the Port of Distribution Server
In the computer where the Distribution Server is installed, open a command prompt and enter the following command and check whether the port is occupied: netstat -an
Free the port by stopping the application using that port or chaning the port of that application to a different port. Distribution Server gets started automatically and update the status back to the Central Server during the next replication time
Change the Distribution Server Port
If you cannot stop the application and free the port, you can change the port number of the Distribution Server as below:
The port number automatically gets updated in the Distrubution Server during the next Replication Interval. Upon successful startup of the Distribution Sevrer the DS Sync Status gets updated.