diff --git a/build-tools/automation/azure-pipelines.yaml b/build-tools/automation/azure-pipelines.yaml
index 9f9454386e3..9f4bdd1eddd 100644
--- a/build-tools/automation/azure-pipelines.yaml
+++ b/build-tools/automation/azure-pipelines.yaml
@@ -417,7 +417,7 @@ extends:
                 $versionEndpoint = 'https://maestro.dot.net/api/assets/darc-version?api-version=2019-01-16'
                 $darcVersion = $(Invoke-WebRequest -Uri $versionEndpoint -UseBasicParsing).Content
                 $arcadeServicesSource = 'https://pkgs.dev.azure.com/dnceng/public/_packaging/dotnet-eng/nuget/v3/index.json'
-                & dotnet tool update microsoft.dotnet.darc --version "$darcVersion" --add-source "$arcadeServicesSource" --tool-path $(Agent.ToolsDirectory)\darc -v n
+                & dotnet tool update microsoft.dotnet.darc --version "$darcVersion" --source "$arcadeServicesSource" --tool-path $(Agent.ToolsDirectory)\darc -v n
                 & $(Agent.ToolsDirectory)\darc\darc add-build-to-channel --default-channels --id $(BARBuildId) --ci --publishing-infra-version 3 --azdev-pat $(System.AccessToken)
             displayName: add build to default darc channel
             condition: and(succeeded(), eq('${{ parameters.pushXAPackagesToMaestro }}', 'true'))
diff --git a/build-tools/automation/yaml-templates/install-dotnet-tool.yaml b/build-tools/automation/yaml-templates/install-dotnet-tool.yaml
index 295bf4029c4..84a7ac7f236 100644
--- a/build-tools/automation/yaml-templates/install-dotnet-tool.yaml
+++ b/build-tools/automation/yaml-templates/install-dotnet-tool.yaml
@@ -21,5 +21,5 @@ steps:
       update ${{ parameters.toolName }} -v:diag
       --tool-path $(Agent.ToolsDirectory)
       --version ${{ parameters.version }}
-      --add-source "https://api.nuget.org/v3/index.json"
+      --source "https://pkgs.dev.azure.com/dnceng/public/_packaging/dotnet-public/nuget/v3/index.json"
 
diff --git a/build-tools/automation/yaml-templates/variables.yaml b/build-tools/automation/yaml-templates/variables.yaml
index 8a9d45d11f7..c683a98c9f9 100644
--- a/build-tools/automation/yaml-templates/variables.yaml
+++ b/build-tools/automation/yaml-templates/variables.yaml
@@ -76,3 +76,9 @@ variables:
   value: true
 - name: DOTNET_GENERATE_ASPNET_CERTIFICATE
   value: false
+# Fix network isolation requirements
+# See https://devdiv.visualstudio.com/DevDiv/_git/Xamarin.yaml-templates/pullrequest/750402
+- name: DOTNET_CLI_WORKLOAD_UPDATE_NOTIFY_DISABLE
+  value: 'true'
+- name: DOTNET_SDK_VULNERABILITY_CHECK_DISABLE
+  value: 'true'