Networking

Testing if a Port is Open With PowerShell

Ever want to confirm that a port is accessible from one computer to another? There’s a PowerShell cmdlet for that, Test-NetConnection. With the -Port option, this cmdlet will do a quick TCP three-way handshake on the remote system to confirm that the service is available and reports back if it succeeded or not. Check out that last line of output TcpTestSucceeded: False. That indicates that this port is not accessible. You can see, however, that the system is reachable via ICMP (Ping), PingSuceeded: True so we know that the remote system is alive, just not listening on the port we want to access.

Speaking at IT/Dev Connections 2017 – San Francisco!

I’m proud to announce that I will be delivering two sessions at IT/Dev Connections in San Francisco! This is my second year at IT/Dev Connections, real content for IT pros! Networking Internals for the SQL Server Professional Tuesday, 10/24/2017: 1:15 pm – 2:30 pm Room: Contiental 7 Abstract Once data leaves your SQL Server do you know what happens or is the world of networking a black box to you? Would you like to know how data is packaged up and transmitted to other systems and what to do when things go wrong?

Speaking at SQLSaturday Chicago – 600!

Speaking at SQLSaturday Chicago! I’m proud to announce that I will be speaking at SQL Saturday Chicago on March 11th 2017! And wow, 600 SQLSaturdays! This one won’t let you down. Check out the amazing schedule! <p> If you don’t know what SQLSaturday is, it’s a whole day of free SQL Server training available to you at no cost! </p> <p> If you haven’t been to a SQLSaturday, what are you waiting for!

Understanding Network Latency and Impact on Availability Group Replication

When designing Availability Group systems one of the first pieces of information I ask clients for is how much transaction log their databases generate. *Roughly*, this is going to account for how much data needs to move between their Availability Group Replicas. With that number we can start working towards the infrastructure requirements for their Availability Group system. I do this because I want to ensure the network has a sufficient amount of bandwidth to move the transaction log generated between all the replicas .