Problem statement: If the connection manager is configured using the server name, it works.
but if the connection manager is configured with the IP Address, it does not work.

Possible Cause: There is a possibility that the Firewall might be creating a block causing the issue.

Resolution/Work Around:  ​
> To rule out the possibility of firewall block, On each server, you need to open the following ports in the Firewall:

1433 for SQL Server

8642 for the APIs

30000 for SAP Business One

27000,27001 for iVend Licenses.

> In addition to the above, If Firewall is Not creating a block then follow the below steps:

- SQL Server configuration manager > SQL server network configuration > protocol for SQLEXPRESS > TCPIP (right click and enable).

- Restart SQL services.