>>Hi,
>>
>>As far as my VFP 9 application working with the SQL Server back end, I know that TCP port 1433 has to be open (for connection to the SQL Server).
>>But what about UPD? Do I need to specify the UPD for the VFP 9 application? The reason I am asking is that a new customer is asking me this question. I have never before had to specify UPD but, just in case, what should be the "rule"?
>
>To avoid confusion it's "UDP", not "UPD": https://en.wikipedia.org/wiki/User_Datagram_Protocol
>
>There's good documentation at https://docs.microsoft.com/en-us/sql/sql-server/install/configure-the-windows-firewall-to-allow-sql-server-access?view=sql-server-ver15 . There are some differences if you use a named instance.
>
>Basically, it's up to you to know which SQL services/components your app uses, and the corresponding ports which need to be open. Then you give the sysadmin that list and they open ports or allow apps appropriately.
>
>For security the rule of thumb is to minimize the number of "allow" firewall rules or open ports. If you're not sure which ones you need, start with a bare minimum (such as TCP port 1433 only) and test all the functions of your app against that. Test in your own environment, if you can - sysadmins don't like people experimenting on their production environments.
>
>There can be a strong temptation to open all the ports in the link above "just to make sure everything works". This is almost always a terrible idea. The only time it may be acceptable is temporarily during troubleshooting. A sysadmin with SQL Server experience will question opening up a bunch of seldom-used ports (and rightfully so).

Thank you for correcting my typo.