Range of ports to be open

In Azure Standard Load Balancer, you can open a whole port range in one load balancing rule — you don't need to define a rule per port.

Azure Portal

1. Go to your Standard Load Balancer in the portal.
2. Select Load balancing rules > + Add.
3. Configure the rule:
   • Frontend IP address → Choose your frontend.
   • Backend pool → Choose the backend pool.
   • Protocol → TCP, UDP, or Both (depending on your workload).
   • Port → Enter a single number if it's one port, but for ranges:
   • Frontend Port Range → 10000-20000
   • Backend Port Range → 10000-20000
   • Other options (session persistence, idle timeout, health probes) → configure as required.
4. Save.

Azure CLI

az network lb rule create \
  --resource-group MyResourceGroup \
  --lb-name MyLoadBalancer \
  --name MediaPortsRule \
  --protocol Udp \
  --frontend-port-range-start 10000 \
  --frontend-port-range-end 20000 \
  --backend-port-range-start 10000 \
  --backend-port-range-end 20000 \
  --frontend-ip-name MyFrontend \
  --backend-pool-name MyBackendPool \
  --probe-name MyHealthProbe

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hth

Marcin

Hello @DABREOBLANCHEBCONE,

Welcome to Microsoft Q&A Platform. Thank you for reaching out & hope you are doing well.

I understand your question regarding opening the media port range 10000–20000 in a single load balancing rule on an Azure Standard Load Balancer.

You can configure a Port Range in One Rule, the Azure Standard Load Balancer allows you to set a continuous port range (such as 10000–20000) in a single load balancing rule. This feature is often used for media streaming, VoIP, or real-time communication scenarios that require multiple open ports.

Steps for Configure:

In the Azure Portal, open your Load Balancer.

Navigate to Load balancing rules and click Add.

Set up the rule with these options:

·       Frontend Port: 10000-20000

·       Backend Port: 10000-20000 (or specify a single port if needed)

·       Protocol: Choose UDP or TCP based on your application's requirement.

·       Backend Pool: Select your backend pool.

·       Health Probe: Use an existing probe (TCP/HTTP/HTTPS).

Click Save to apply the rule.

If you are unable to config via Azure portal, you can config via CLI.

az network lb rule create \
  --resource-group MyResourceGroup \
  --lb-name MyLoadBalancer \
  --name MediaPortsRule \
  --protocol Udp \
  --frontend-port-range-start 10000 \
  --frontend-port-range-end 20000 \
  --backend-port-range-start 10000 \
  --backend-port-range-end 20000 \
  --frontend-ip-name MyFrontend \
  --backend-pool-name MyBackendPool \
  --probe-name MyHealthProbe

Note: Port range rules are only available with the Azure Standard Load Balancer and not with the Basic SKU. When setting up these rules, make sure your Network Security Groups (NSGs) and firewall settings also permit traffic for the specified port range to prevent connectivity problems. For UDP traffic, use a TCP or HTTP health probe since UDP probes are not supported in Azure Load Balancer. Because this setup uses a large port range, it’s best to review the configuration for security and limit access to trusted sources to keep the network secure.

__Azure load balancer overview: What is Azure Load Balancer? - Azure Load Balancer | Microsoft Learn

Kindly let us know if the above helps or you need further assistance on this issue.

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