Deployment Guide

Forwarding Features

Flow Failover

This feature provides failover support if a controller is unavailable. If the connection to a controller is lost,

installed flows are retained and used for forwarding traffic until they are updated. This feature is enabled

by default but you can disable failover on individual instances by using the use the no fail-mode

secure command. If you disable failover, all flows to the unavailable controller are dropped. For more

information, refer to the fail-mode secure command.

Flow Misses

By default, flows that do not reach their intended destination (flow misses), are copied to the controller.

To disable this feature on an OF instance, configure the controller to drop flow misses instead of copying

them to the controller by using the flow-misses drop command. For more information, refer to the

flow-misses drop command.

Default VLAN

In the previous version of OpenFlow, some packet types, such as untagged ARP broadcasts, received on

an OF port could not be forwarded from a physical port and could only be copied to the controller. To

resolve this issue, assign a default VLAN to the OF ports using the openflow vlan command. If you do

not assign a VLAN, the software selects one when you create the first OF instance. The default VLAN

applies to all OF instances and can only be configured if you have not configured any OF instances. For

more information, refer to the

openflow vlan command.

Source Suppression

Source suppression prevents received packets from being transmitted from the ingress port. Source

suppression is enabled by default and is applied to all instances on the switch. If you disable source

suppression, received packets can be transmitted from the ingress port.

NOTE: If you disable source suppression, the following conditions apply:

• Dell Networking does not recommend enabling legacy features.

• You cannot enable Hybrid mode.

• If you install flows using OFPP_FLOOD or OFPP_ALL, traffic loops may occur. If you disable

source suppression, Dell Networking recommends that you do not install flows using these

parameters.

For more information, refer to the src-suppression command.