Fail-to-Block Mode
This chapter provides information about the fail-to-block mode on SteelHead and SteelFusion appliances and details the hardware and software versions that support fail-to-block mode. It includes the following sections:
This chapter assumes you have installed and configured the appliance.
Overview
This section describes fail-to-block mode as compared to the default fail-to-bypass mode.
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 is 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 do not detect a link.
RiOS supports fail-to-block mode on all cards, including cards that do not 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:
• Kernel crash
• Hardware failure
• Power loss
SteelHead CX, EX, DX, Interceptor, and SteelFusion NICs and Fail-to-Block Functionality
All SteelHead CX, DX, EX, Interceptor 9600, and SteelFusion NICs support fail-to-block mode.
SteelHead xx50 NICs and Fail-to-Block Functionality
The following table lists the NICs that support the following functionalities in the SteelHead xx50 appliances:
• Blocks on kernel crash
• Blocks on hardware failure
• Blocks on power loss
NIC Description | Manufacturing Part # |
Two-Port SX Multimode Fiber GbE PCIe Card | 410-00101-01 |
Four-Port SX Multimode Fiber GbE PCIe Card | 410-00102-01 |
Four-Port Copper GbE PCIe Card | 410-00103-01 |
Two-Port LX Single Mode Fiber GbE PCIe Card | 410-00105-01 |
Four-Port LX Single Mode Fiber GbE PCIe Card | 410-00106-01 |
Two-Port FX Multimode Fiber 100-Mbps PCIe Card | 410-00107-01 |
Two-Port LR Single Mode Fiber 10-GbE PCIe Card | 410-00301-01 |
Two-Port SR Multimode Fiber 10-GbE PCIe Card | 410-00302-01 |
Fail-to-Block CLI Commands
You can enable the fail-to-block mode on a per interface basis.
Fail-to-Block CLI commands:
• no interface <interface-name> fail-to-bypass enable: Sets the interface to block when there is a failure.
• interface <interface-name> fail-to-bypass enable: Sets the interface to bypass when there is a failure.