Tag: SQL Server Networking

Networking concepts and troubleshooting for SQL Server, including ports, TCP/IP configuration, connectivity testing, firewalls, and client connection behaviour.

  • Check SQL Server Connection Encryption and Protocol

    Modern SQL Server environments often use encrypted connections by default, but that does not always mean what people think it means. When troubleshooting connectivity problems, certificate errors, performance questions, or unexpected client behaviour, DBAs usually need to answer one very specific question: What protocol and encryption is this connection actually using right now? This post…

  • sqlcmd Examples for SQL Server

    sqlcmd is a command line utility for connecting to SQL Server and executing Transact-SQL without a GUI. It is commonly used for automation, scripting, remote administration, and incident response, especially in environments where SSMS is unavailable, inappropriate, or too heavy. This post covers sqlcmd usage from a DBA perspective, how to find or install it,…

  • SSMS Certificate Chain Not Trusted Error (Trust Server Certificate Fix)

    If you’ve recently upgraded SQL Server Management Studio and suddenly can’t connect to SQL Server, you may see an SSL or certificate error during login. This commonly appears after upgrading to newer SSMS versions and is caused by a change in how SSMS handles encryption by default. The good news: this is usually quick to…

  • SQL Server Default Ports

    By default, the SQL Server Database Engine listens on TCP port 1433. This is useful to know, but it is not something you should rely on blindly. SQL Server can be configured to listen on different ports, and this is common on hosts running multiple SQL Server instances where each instance requires its own port.…

  • Enabling TCP Connections in SQL Server

    TCP/IP must be enabled in SQL Server for remote connections to work. If it’s disabled, applications can’t connect; even if authentication, ports, and firewall rules are all correct. This post shows two reliable ways to enable TCP connections in SQL Server: Both approaches require a service restart before changes take effect. When You Need to…

  • Testing Remote Server Port Connectivity with PowerShell

    Testing connectivity to remote server ports is a basic skill every DBA should have. Not just DBAs either — anyone running production systems needs to be able to answer one simple question quickly: Can this server actually reach that server on this port? This post shows two reliable ways to test whether a remote port…

  • How to Check Listening Ports on Windows

    When troubleshooting connectivity issues, it’s often not enough to test whether a remote port is reachable. You also need to know what is actually listening on a port locally, or whether anything is listening at all. This post focuses on the local side of the equation, what is listening on the machine itself and which…