Functional Components - Cisco ASR 9000 Series User Configuration Manual

Implementing Open Flow Agent
• Native dedicated CLI and troubleshooting
• High Availability

Functional Components

OpenFlow supports the configuration of multiple controllers for a logical switch. The Openflow agent can
connect to a single controller or up to 8 controllers. It creates connections to all configured controllers to
provide the controllers access to the OpenFlow logical switch flow tables and interfaces. It will receive flow
entries from the controllers and report interface and flow status and statistics to the controllers.
The set nexthop action for layer 3 matches is implemented through a Cisco extension to the OpenFlow (1.0
and 1.3) protocol.
OFA on ASR 9000 series routers
The OpenFlow Agent supports multiple logical switch instances on ASR9K platform, with each logical switch
managing a set of physical/logical interfaces, an L2 bridge domain or a VRF. Each logical switch may have
one openflow connection to a single controller, or multiple connects for reliability, each to a different controller
. The openflow connection to the controller uses standard TLS or plain TCP.
When the logical switch initialises a connection to the configured controller, the signaling version for the
agent-controller connection is negotiated based on the bitmap version supported on both- agent and controller
sides. When a logical switch starts up for the first time or at the time a logical switch loses contact with all
controllers, it operates in either fail-secure mode (with default-set rule) or fail-standalone mode depending
on the CLI of fail-standalone (on or off). The default for configuration is in the fail-secure mode.
OFA on OnePK
OnePK and OpenFlow have overlapping goals. The OpenFlow protocol features and switch model have
similarities with the Policy and DataPath Service Sets. Building the OpenFlow Agent with onePK increases
portability of the OpenFlow Agent. OpenFlow Agent is designed on the top of onePK presentation layer and
it depends on following onePK Service Sets:
• Element SS Presentation Layer for interface configurations, statistics and state
• Policy SS Presentation Layer for match-action flow processing and flow stats, as well as hardware
• DataPath SS Presentation Layer for packet capture and inject
• Routing Service Set for VRF support
OpenFlow Matches
Matches are supported on ingress port and various packet headers depending upon the packet type. Flows can
have priorities. Hence, the highest priority flow entry that matches the packet gets selected.
Following table shows the list of matches supported on ASR9K for various table types:
capabilities
Cisco ASR 9000 Series Aggregation Services Router System Management Configuration Guide, Release 5.1.x
Functional Components
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