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jameshao's avatar
jameshao
Copper Contributor
Feb 09, 2025
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Basic LoadBalancer Upgrade - no outbound rule created

The AzureBasicLoadBalancerUpgrade module used for upgrading load balancer from basic to standard sku. It doesn't seem to create outbound rule when there's no existing backend pool in the basic LB. It can create the outbound rule if there is pre-existing backendpool in the basic lb.

I know the outbound connection is implicit in the basic LB and I want to maintain the outbound connection after upgrading to standard sku. So my question is whether it's ok to create a backendpool for the standard LB using all the nics from inbound NAT rule then create a outbound rule based on the new backend pool? Is there's any security concern by doing this way?

  • How about creating a backend pool for the Standard Load Balancer using all the NICs from the inbound NAT rule and then creating an outbound rule based on this new backend pool?

    However, there are a few security considerations:

    1. Security Groups: Ensure that the Network Security Groups (NSGs) associated with your backend pool are properly configured to allow only the necessary traffic. This helps in maintaining a secure environment by restricting unwanted access.
    2. Public IP Addresses: If your backend VMs or VMSS instances have instance-level public IP addresses, ensure that these are correctly configured to avoid conflicts or exposure.
    3. Monitoring and Logging: Enable monitoring and logging to keep track of the traffic and detect any unusual activity. Azure Monitor and Azure Security Center can help with this.
  • NKUGAN's avatar
    NKUGAN
    Brass Contributor

    Creating a backend pool for a Standard Load Balancer using all the NICs from an inbound NAT rule and then creating an outbound rule based on this new backend pool is a common approach. However, there are a few security considerations to keep in mind:

    Network Security Groups (NSGs): Ensure that the NSGs associated with your backend pool are properly configured to allow only the necessary traffic. This helps in maintaining a secure environment by restricting unwanted access.

    Public IP Addresses: If your backend VMs or VMSS instances have instance-level public IP addresses, ensure that these are correctly configured to avoid conflicts or exposure.

    Monitoring and Logging: Enable monitoring and logging to keep track of the traffic and detect any unusual activity. Azure Monitor and Azure Security Center can help with this.

    Outbound Rule Configuration: When configuring the outbound rule, make sure to define the SNAT (source network address translation) behavior explicitly. This includes specifying which virtual machines are translated to which public IP addresses, how SNAT ports are allocated, and the protocols to provide outbound translation for. Outbound rules Azure Load Balancer | Microsoft Learn

  • How about creating a backend pool for the Standard Load Balancer using all the NICs from the inbound NAT rule and then creating an outbound rule based on this new backend pool?

    However, there are a few security considerations:

    1. Security Groups: Ensure that the Network Security Groups (NSGs) associated with your backend pool are properly configured to allow only the necessary traffic. This helps in maintaining a secure environment by restricting unwanted access.
    2. Public IP Addresses: If your backend VMs or VMSS instances have instance-level public IP addresses, ensure that these are correctly configured to avoid conflicts or exposure.
    3. Monitoring and Logging: Enable monitoring and logging to keep track of the traffic and detect any unusual activity. Azure Monitor and Azure Security Center can help with this.

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