ADC

Disabling steering on the cluster backplane

August 20, 2024

Contributed by:

C C S

Note

Supported from NetScaler 11 onwards.

The default behavior of a Citrix ADC cluster is to direct the traffic that it receives (flow receiver) to another node (flow processor) that must then process the traffic. This process of directing the traffic from flow receiver to flow processor occurs over the cluster backplane and is called steering.

If required, you can disable steering so that the process becomes local to the flow receiver and therefore makes the flow receiver as the flow processor. Such a configuration setup can come handy when you have a high latency link.

Note

This configuration is applicable only for striped virtual servers.

For partially striped virtual servers, if the flow receiver is a non-owner node, the traffic is steered to a owner node. If however, the flow receiver is a owner node, then steering is disabled.
For spotted virtual servers, flow receiver is the flow processor, and hence there is no need for steering.

Some points to remember when disabling the steering mechanism:

Striped SNIPs are not supported as steering is disabled.
MPTCP and FTP does not work.
L2 mode must be disabled.
If USIP is enabled, traffic may not reach back to the same node as the steering is disabled.
Traffic that is directed to the cluster IP address is steered to the configuration coordinator.
When a node joins or leaves a cluster, it is possible that more than 1/N connections will be affected. This is due to the fact that a change in the nodes available, may cause the routes to be rehashed. As a result, the traffic will be routed to another node and due to the non-availability of steering, the traffic will not be processed.

Steering can be disabled at the individual virtual server level or at the global level. The global configuration takes precedence over the virtual server setting.

Disabling backplane steering for all striped virtual servers

Configured at cluster instance level. Traffic meant for any striped virtual server will not be steered on cluster backplane.

add cluster instance \<clId\> -processLocal ENABLED
Disabling backplane steering for a specific striped virtual server

Configured on a striped virtual server. Traffic meant for the virtual server will not be steered on cluster backplane.

add lb vserver <name> <serviceType> -processLocal ENABLED

The official version of this content is in English. Some of the Cloud Software Group documentation content is machine translated for your convenience only. Cloud Software Group has no control over machine-translated content, which may contain errors, inaccuracies or unsuitable language. No warranty of any kind, either expressed or implied, is made as to the accuracy, reliability, suitability, or correctness of any translations made from the English original into any other language, or that your Cloud Software Group product or service conforms to any machine translated content, and any warranty provided under the applicable end user license agreement or terms of service, or any other agreement with Cloud Software Group, that the product or service conforms with any documentation shall not apply to the extent that such documentation has been machine translated. Cloud Software Group will not be held responsible for any damage or issues that may arise from using machine-translated content.

Disabling steering on the cluster backplane

August 20, 2024

Contributed by:

C C S

August 20, 2024

Contributed by:

C C S

Disabling steering on the cluster backplane

In this article