Users Guide

1656 OpenFlow
When using multiple hardware tables, it is possible to set up the hardware so
that, for example, the MAC Forwarding Table and OpenFlow 1.0 Rule Table
match the same packet. If the packet matches multiple slices in the IFP, the
hardware performs all non-conflicting actions on the packet. For example, the
OpenFlow 1.0 Rule Table may set the packet priority and the MAC
Forwarding Table may direct the packet to a specific output port.
If the packet actions conflict, the egress action is not predictable. The
controller-based applications should take care not to insert flow with
conflicting actions.
If the packet matches an IFP rule installed by a different component, such as
QoS. any conflicting actions are generally resolved in favor of the other
component. The IFP slices allocated to the OpenFlow component have the
lowest priority except for the system rules. The OpenFlow actions override
actions installed by the system rules.
Although the OpenFlow IFP slices are lower priority than IFP slices used by
other Dell EMC Networking OpenFlow Hybrid components, the IFP itself is
positioned in the ingress pipeline after the forwarding database and the
routing tables. This means that IFP rules inserted by the OpenFlow feature
can affect switching and routing decisions.
VFP-based flows also may affect switching decisions and alter switching
protocols behavior by changing MAC addresses or/and VLAN IDs.
To avoid interfering with non-OpenFlow traffic, the rules should be qualified
with a VLAN ID reserved for the OpenFlow traffic. The Dell EMC
Networking OpenFlow Hybrid switch does not enforce any specific VLAN
IDs and also accepts wildcard VLAN IDs, so it is up to the OpenFlow
Controller to configure the switch correctly.
25 MAC Forwarding
Table
IFP table containing multicast and unicast DA-
MAC-based forwarding rules.
26–31 Reserved Unused
32–255 Unsupported The enhanced OpenFlow 1.0 protocol only
supports table IDs 0 to 31.
Table 48-2. Flow Table Identifiers (Continued)
ID Usage Description