Frequently Asked Questions: NSX-T Load Balancer Configuration
Article ID: 425620
Updated On:
Products
Issue/Introduction
Common Considerations for NSX-T LB Virtual Server Configuration
Environment
VMware NSX T Load Balancer
Resolution
Q1. What is a Load Balancer Virtual Server in NSX-T?
Answer:
A Load Balancer Virtual Server in NSX-T represents the front-end listener that accepts client traffic. It defines the virtual IP address (VIP), listening port(s), application profile, and the associated server pool used to distribute traffic to backend members.
Q2. Can a single Virtual Server be configured with multiple listening ports?
Answer:
Yes. A single Virtual Server can be configured with multiple listening ports. This allows the same virtual IP to handle traffic on different ports while forwarding requests to the appropriate backend services.
Q3. Is it supported to create a Server Pool without specifying a member port?
Answer:
When creating a Server Pool, you only specify the pool members. A member port is not defined at the Server Pool level; instead, the port is configured as part of the virtual server.
Q4. How is the backend port determined when the Server Pool member port is not defined?
Answer:
When the pool member port is not specified, the port used for backend traffic forwarding is inherited from the Virtual Server listener configuration. This behavior avoids redundant configuration and is supported in NSX-T.
Q5. Can multiple Health Monitors be attached to a single Server Pool?
Answer:
Yes. Multiple Health Monitors can be attached to the same Server Pool. Each Health Monitor can be configured to monitor a different port or protocol as required.
Q6. Is it supported to attach Health Monitors that monitor different ports to the same Server Pool?
Answer:
Yes. You can configure multiple Health Monitors, each monitoring a different port, and attach all of them to the same Server Pool. This is useful when backend services expose multiple ports that require independent health validation.
Q7. Can a Server Pool have a mix of TCP and URL-based Health Monitors?
Answer:
Yes. A Server Pool can have a mix of TCP-based and URL-based (HTTP/HTTPS) Health Monitors attached. NSX-T evaluates all associated health monitors, and pool member health is determined based on the combined results.
Q8. What role do Application Profiles play in Virtual Server configuration?
Answer:
Application Profiles define protocol-specific behavior such as HTTP, HTTPS, TCP, or UDP handling. They control connection handling, persistence, timeouts, and protocol behavior and are required for proper Virtual Server operation.
Q9. Is a Health Monitor mandatory for a Server Pool?
Answer:
No. Health Monitors are not mandatory. However, it is strongly recommended to configure Health Monitors in production environments to ensure traffic is not forwarded to unhealthy backend members.
Q10. Is there a required sequence for creating Health Monitors, Server Pools, and Virtual Servers?
Answer:
There is no strict requirement on the order of object creation. NSX-T allows flexibility in how these objects are created and associated.
Q11. What is the recommended best-practice sequence for object creation?
Answer:
From a best practice and clarity perspective, it is generally recommended to create objects in the following order:
-
Health Monitors
-
Server Pool
-
Virtual Server
This approach improves configuration clarity, allows easier validation, and helps avoid interim misconfigurations.
Q12. Can objects be created directly from the Virtual Server UI?
Answer:
Yes. You may start by creating the Virtual Server and, from the UI, create and attach a new Server Pool. Health Monitors can then be created and associated with the Server Pool as needed.
As long as all referenced objects (Server Pool and Health Monitors) are correctly defined and attached before the configuration is finalized and put into use, the configuration is considered valid and supported.
Feedback
