Azure Load Balancer SKUs

Azure Load Balancer has two SKUs.

SKU comparison

Load balancer supports both Standard and Basic SKUs. These SKUs differ in scenario scale, features, and pricing. Any scenario that's possible with Basic load balancer can be created with Standard load balancer.

To compare and understand the differences, see the following table. For more information, see Azure Standard Load Balancer overview.

Note

Microsoft recommends Standard load balancer. Standalone VMs, availability sets, and virtual machine scale sets can be connected to only one SKU, never both. Load balancer and the public IP address SKU must match when you use them with public IP addresses. Load balancer and public IP SKUs aren't mutable.

Standard Load Balancer Basic Load Balancer
Backend pool size Supports up to 1000 instances. Supports up to 300 instances.
Backend pool endpoints Any virtual machines or virtual machine scale sets in a single virtual network. Virtual machines in a single availability set or virtual machine scale set.
Health probes TCP, HTTP, HTTPS TCP, HTTP
Health probe down behavior TCP connections stay alive on an instance probe down and on all probes down. TCP connections stay alive on an instance probe down. All TCP connections end when all probes are down.
Availability Zones Zone-redundant and zonal frontends for inbound and outbound traffic. Not available
Diagnostics Azure Monitor multi-dimensional metrics Not supported
HA Ports Available for Internal Load Balancer Not available
Secure by default Closed to inbound flows unless allowed by a network security group. Internal traffic from the virtual network to the internal load balancer is allowed. Open by default. Network security group optional.
Outbound Rules Declarative outbound NAT configuration Not available
TCP Reset on Idle Available on any rule Not available
Multiple front ends Inbound and outbound Inbound only
Management Operations Most operations < 30 seconds 60-90+ seconds typical
SLA 99.99% Not available
Global VNet Peering Support Standard ILB is supported via Global VNet Peering Not supported

For more information, see Load balancer limits. For Standard Load Balancer details, see overview, pricing, and SLA.

Limitations

  • SKUs aren't mutable. You can't change the SKU of an existing resource.
  • A standalone virtual machine resource, availability set resource, or virtual machine scale set resource can reference one SKU, never both.
  • Move operations:
    • Resource group move operations (within same subscription) are supported for Standard Load Balancer and Standard Public IP.
    • Subscription group move operations are not supported for Standard Load Balancer and Standard Public IP resources.

Next steps