This chapter provides information about the fail-to-block mode on SteelHead CX x80, SteelHead CX xx80, Interceptor 9600, and Interceptor 9800 appliances.

Fail-to-bypass mode lets the network maintain connectivity in the event of a failure, without optimization. With fail-to-block mode enabled in a redundant network path environment, traffic is blocked and rerouted to an optimized backup path in the event of a failure.

This feature is useful only if the network has a routing or switching infrastructure that can automatically divert traffic from the link to the optimized backup path. In an active-backup redundant network setup, the active path is configured to use fail-to-block mode, and the backup path is configured to use fail-to-bypass mode, thus traffic continues to be optimized on the backup path if there’s a failure on the active path. In the event of a failure, the LAN and WAN interfaces power down. From a connected router or switch perspective, those devices don’t detect a link.

RiOS supports fail-to-block mode on all cards, including cards that don’t have hardware fail-to-block capabilities, allowing fail-to-block mode functionality with most NICs while the operating system is running.

The following events trigger fail-to-block mode if the feature is enabled:

You can enable the fail-to-block mode on a per interface basis.