NSX Design Notes (6/10) – Load Balancer

Load balancing service is provided by NSX Edge device.

1) Features & Functionality

  1. Modes:
    1. One-Arm
    2. Inline.
    3. Currently NSX load balancer does not support DSR.
  2. Supports HA: Check “Enable High Availability” while deploying NSX Edge.
  3. Supported Applications:
    1. TCP
    2. UDP ( from NSX 6.1)
  4. Load Balancing Distribution Algorithms
    1. Round Robin: Each server is used in turn according to the weight assigned to it. This is the smoothest and fairest algorithm when the server’s processing time remains equally distributed.
    2. Least Connections: New connections are sent to the server with the fewest connections.
    3. IP Hash: Selects a server based on a hash of the source and destination IP address of each packet.
    4. URI: The left part of the URI (before the question mark) is hashed and divided by the total weight of the running servers. The result designates which server will receive the request. This ensures that a URI is always directed to the same server as long as no server goes up or down.
    6. URL :
  5. Health Checks
    1. TCP
    2. HTTP/HTTPs
  6. Persistence :
    2. HTTP : Cookie, SOURCEIP
    3. HTTPS: Cookie, ssl_session_id (SSL Pass-through enabled) , SOURCEIP
  7. External Integration: Service Insertion allows
    the load balancer to work with third party vendor appliances.
  8. L7 manipulation, including URL block, URL rewrite, and content rewrite
  9. Connection throttling of maximum connections and connections per second.

2) Proxy Mode


1) Simple to Deploy and provided great flexibility
2) Allows deployment of Load Balancers without modifying NSX Edge Service Gateway.
1) More NSX Edges
2) Servers in datacenters do not have visibility of Client IPs

3) Inline Mode

1) Provides full visibility into client IPs to servers in datacenters

1) Modifies Central Edge Service Gateway which is providing L3 services.

NSX Design Notes (5/10) – Micro Segmentation
NSX Design Notes (7/10) – VPN
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