Administrator Guide

1708 OpenFlow
Group Table
The group abstraction enables OpenFlow to represent a set of ports as a single
entity for forwarding packets. Different types of groups are provided, to
represent different abstractions such as multicasting or multipathing. Each
group is composed of a set group buckets, and each group bucket contains the
set of actions to be applied before forwarding to the port. Groups buckets can
also forward to other groups, enabling groups to be chained together.
• Group indirection to represent a set of ports.
• Group table with three types of groups:
– All — used for multicast and flooding
– Select — used for multipath
– Indirect — simple indirection
• Group action to direct a flow to a group.
• Group buckets contains actions related to the individual port
A group table consists of group entries. The ability for a flow entry to point to
a group enables OpenFlow to represent additional methods of forwarding
(e.g., select and all).
Each group entry is identified by its group identifier and contains:
• group identifier: a 32 bit unsigned integer uniquely identifying the group
on the OpenFlow switch.
• group type: to determine group semantics.
• counters: updated when packets are processed by a group.
• action buckets: an ordered list of action buckets, where each action bucket
contains a set of actions to execute and associated parameters. The actions
in a bucket are always applied as an action set.
Dell EMC Networking OpenFlow Hybrid does not assign any special meaning
to the group ID. The OpenFlow controller is free to use any valid group
identifier. Dell EMC Networking OpenFlow Hybrid determines the type of
hardware group to create based on the group type passed from the OpenFlow
controller.
• The “Indirect” group type simply creates a next-hop. (L3 Unicast group
entry)