Data Center SSL offload

Data center SSL offload is a communication method where all HTTPS traffic is terminated at the load balancer (LB) and all communication behind it (inside the data center) is over non-HTTPS communication. Data center SSL offload relieves data center servers of the continuous encryption and decryption of HTTPS traffic. The decryption of HTTPS traffic is offloaded to a separate device designed specifically to perform SSL termination (the LB). As such, Data center SSL offload is not supported on consolidated environments and requires a LB to be deployed.

Load balancer external and internal addresses

When Data Center SSL Offload is enabled, the system supports the use of an external and internal load balancer addresses:

  • The external address is used for HTTPS communication between desktops or site servers to the load balancer and creates a single point of access to the data center.

  • The internal address is used for HTTP communication between the data center servers and the load balancer.

Separating the addresses is optional and the same address may be used for both internal and external communication. However, since communication to the external address is done over HTTPS, and communication to the internal address is done over HTTP, it is recommended to use separate addresses in different network segments, or to carefully restrict the access to the non-HTTPS port to data center servers only.

Data Center SSL offload data flow

SSL offload data flow in the Data Center

For a more detailed explanation, the table provides communication methods used in the system flows between the source and target server.

Source

Target

Com.

Comments

Desktop

LB

HTTPS

LB external address is used

DC server

LB

HTTP

LB internal address is used

DC server

DC server

HTTP

 

Site server

LB

HTTPS

LB external address is used

Site server

DC server

N/A

Site servers communicate through the LB

Desktop/Application server

HTTPS enabled site

HTTPS

 

Desktop/Application server

HTTPS disabled site

HTTP

 

Load Balancer(LB) (Technologies, Security, and Networking DRG)