Configure TCP reset and idle timeout for Azure Load Balancer

To set the idle timeout and TCP reset for a load balancer, edit the load-balanced rule.

1. Sign in to the Azure portal.
2. In the left-hand menu, select Resource groups.
3. Select the resource group for your load balancer. In this example, the resource group is named myResourceGroup.
4. Select your load balancer. In this example, the load balancer is named myLoadBalancer.
5. In Settings, select Load balancing rules.
6. Select your load-balancing rule. In this example, the load-balancing rule is named myLBrule.
7. In the load-balancing rule, input your timeout value into Idle timeout (minutes).
8. Under TCP reset, select Enabled.
9. Select Save.
10. Reopen myLBrule and confirm that Idle timeout (minutes) shows your value and TCP reset shows Enabled.

To set the idle timeout and TCP reset, set values in the following load-balancing rule parameters with Set-AzLoadBalancer:

• IdleTimeoutInMinutes
• EnableTcpReset

If you choose to install and use PowerShell locally, this article requires the Azure PowerShell module version 5.4.1 or later. Run Get-Module -ListAvailable Az to find the installed version. If you need to upgrade, see Install Azure PowerShell module. If you're running PowerShell locally, you also need to run Connect-AzAccount to create a connection with Azure.

Replace the following examples with the values from your resources:

• myResourceGroup
• myLoadBalancer
• myLBrule

Select the rule by name so that you update the intended rule rather than whichever rule happens to be first in the collection.

$lb = Get-AzLoadBalancer -Name "myLoadBalancer" -ResourceGroup "myResourceGroup"
$rule = $lb.LoadBalancingRules | Where-Object { $_.Name -eq "myLBrule" }
$rule.IdleTimeoutInMinutes = '15'
$rule.EnableTcpReset = $true
Set-AzLoadBalancer -LoadBalancer $lb

Confirm the saved values on the intended rule:

$Rule |  Select-Object Name, IdleTimeoutInMinutes, EnableTcpReset

To set the idle timeout and TCP reset, use the following parameters for az network lb rule update:

• --idle-timeout
• --enable-tcp-reset

Validate your environment before you begin:

• Sign in to the Azure portal and check that your subscription is active by running az login.
• Check your version of the Azure CLI in a terminal or command window by running az --version. For the latest version, see the latest release notes.
  • If you don't have the latest version, update your installation by following the installation guide for your operating system or platform.

Replace the following examples with the values from your resources:

• myResourceGroup
• myLoadBalancer
• myLBrule

az network lb rule update \
    --resource-group myResourceGroup \
    --name myLBrule \
    --lb-name myLoadBalancer \
    --idle-timeout 15 \
    --enable-tcp-reset true

Confirm the saved values on the intended rule:

az network lb rule show \
    --resource-group myResourceGroup \
    --name myLBrule \
    --lb-name myLoadBalancer \
    --query "{name:name, idleTimeoutInMinutes:idleTimeoutInMinutes, enableTcpReset:enableTcpReset}"