Tuesday, July 25, 2023

Creating Azure Route Tables, UDRs, and IPGroups with PowerShell and Excel reference files

I recently worked with a colleague to complete a deployment and one of the laborious activities we had to complete were:

  1. Create Route Tables with UDRs (user defined routes)
  2. IP Groups

There are a significant amount of entries for both resources and while it was possible to create these manually in the portal, I felt that it was better to create a PowerShell script to accelerate the creation and minimize human typo and copy and paste errors. The 2 scripts I created for this are as follows.

Creating Route Tables and UDRs

The PowerShell script I created, which can be found here in my Github repo:, will read an Excel file and create the route tables and the corresponding UDRs (all route tables should have the same UDRs). One of the conditions I’ve added in is an IF statement that checks to see if the UDR to be added is the same subnet as where the route table will be attached. If it is the same, then the script will skip the creation of the UDR additional so we don’t end up routing traffic from the same subnet up to the firewall. The naming convention designed allows me to compare the Route Table and UDR name to determine if it is a match but if your environment is different then you’ll need to adjust the check. Here are screenshots of the sample spreadsheet that is read:


Create IPGroups

There were many IP Groups that needed to be created as well because the environment had an IP Group for each subnet. The script that will read an Excel file and create the list of IP Groups can be found here at my GitHub repo:

Here are sample screenshots of the Excel file:


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