OpenFlow is the communications interface defined between the control and forwarding layers of a Software-Defined Networking architecture. With OpenFlow, you can perform centralized data forwarding management for physical and virtual devices through controllers.

OpenFlow network components

OpenFlow separates the data forwarding and routing decision functions. It keeps the flow-based forwarding function and employs a separate controller to make routing decisions. An OpenFlow switch communicates with the controller through an OpenFlow channel. An OpenFlow channel can be encrypted by using TLS or run directly over TCP. An OpenFlow switch exchanges control messages with the controller through an OpenFlow channel to perform the following operations:

· Receive flow table entries or data from the controller.

· Report information to the controller.

Unless otherwise stated, a switch refers to an OpenFlow switch throughout this document.

Figure 1 OpenFlow network diagram

OpenFlow switch

OpenFlow switches include the following types:

· OpenFlow-only—Supports only OpenFlow operation.

· OpenFlow-hybrid—Supports both OpenFlow operation and traditional Ethernet switching operation.

OpenFlow port

OpenFlow supports the following types of ports:

· Physical port—Corresponds to a hardware interface, such as an Ethernet interface. A physical port can be either an ingress port or an output port.

· Logical port—Does not correspond to a hardware interface and might be defined by non-OpenFlow methods. For example, aggregate interfaces and tunnel interfaces are logical ports. A logical port can be either an ingress port or an output port.

· Reserved port—Defined by OpenFlow to specify forwarding actions. Reserved ports include the following types:

¡ All—All ports that can be used to forward a packet.

¡ Controller—OpenFlow controller.

¡ Table—Flow table.

¡ In port—Packet ingress port.

¡ Any—Generic port description.

¡ Local—Local CPU.

¡ Normal—Normal forwarding process.

¡ Flood—Flooding.

Except the Any type, all reserved ports can be used as output ports. Only the Controller and Local types can be used as ingress ports.

OpenFlow instance

Unless otherwise stated, an OpenFlow switch refers to an OpenFlow instance throughout this document.

You can configure one or more OpenFlow instances on the same device. A controller considers each OpenFlow instance as a separate OpenFlow switch and deploys forwarding instructions to it.

OpenFlow instance mode

An OpenFlow instance operates in one of the following modes:

· Global mode—When the global mode is enabled for an OpenFlow instance, the flow entries take effect on packets within the network. All service interfaces on the device belong to the OpenFlow instance.

· VLAN mode—When the VLAN mode is enabled for an OpenFlow instance, the flow entries take effect only on packets within VLANs associated with the OpenFlow instance. You must associate the OpenFlow instance with VLANs. All interfaces in the associated VLANs belong to the OpenFlow instance.

· Port mode—When the port mode is enabled for an OpenFlow instance, the flow entries take effect only on packets on interfaces bound to the OpenFlow instance. You must manually bind interfaces to the OpenFlow instance.

Activation and reactivation

The configurations for an OpenFlow instance take effect only after the OpenFlow instance is activated.

The controller can deploy flow entries to an OpenFlow instance only after the OpenFlow instance reports the following device information to the controller:

· Capabilities supported by OpenFlow.

· Information about ports that belong to the OpenFlow instance.

An activated OpenFlow instance must be reactivated when any of the OpenFlow instance configurations are changed.

After reactivation, the OpenFlow instance is disconnected from all controllers and then reconnected to them.

OpenFlow instance port

An OpenFlow switch sends information about the following ports to the controller:

· Physical ports.

· Logical ports.

· Reserved ports of the Local type.

In loosen mode, a port belongs to the OpenFlow instance when VLANs associated with the OpenFlow instance overlap with the port's allowed VLANs. Otherwise, a port belongs to an OpenFlow instance only when VLANs associated with the OpenFlow instance are within the port's allowed VLAN list.

OpenFlow flow table

An OpenFlow switch matches packets with one or more flow tables. A flow table contains flow entries, and packets are matched based on the matching precedence of flow entries.

Flow table types

OpenFlow flow tables include the following types:

· MAC-IP—Combines the MAC address table and FIB table.

A MAC-IP flow table provides the following match fields:

¡ Destination MAC address.

¡ VLAN.

¡ Destination IP address.

A MAC-IP flow table provides the following actions:

¡ Modifying the destination MAC address.

¡ Modifying the source MAC address.

¡ Modifying the VLAN.

¡ Modifying the tunnel ID.

¡ Specifying the output port.

For more information, see "Appendix B MAC-IP flow table."

· Extensibility—Uses ACLs to match packets.

Flow entry

A flow entry contains the following fields:

· Match fields—Matching rules of the flow entry. These contain the ingress port, packet headers, and metadata specified by the previous table.

· Priority—Matching precedence of the flow entry. When a packet is matched with the flow table, only the highest priority flow entry that matches the packet is selected.

· Counters—Counts of the packets and bytes that match the flow entry.

· Instructions—Used to modify the action set or pipeline processing. Instructions include the following types:

¡ Meter—Directs the packets to the specified meter to rate limit the packets.

¡ Apply-Actions—Applies the specified actions in the action list immediately.

¡ Clear-Actions—Clears all actions in the action set immediately.

¡ Write-Actions—Modifies all actions in the action set immediately.

¡ Write-Metadata—Modifies packets between two flow tables if multiple flow tables exist.

¡ Goto-Table—Indicates the next flow table in the processing pipeline.

Actions are executed in one of the following ways:

¡ Action Set—When the instruction set of a flow entry does not contain a Goto-Table instruction, pipeline processing stops. Then, the actions in the action set are executed in the order specified by the instruction list. An action set contains a maximum of one action of each type.

¡ Action List—The actions in the action list are executed immediately in the order specified by the action list. The effect of those actions is cumulative.

Actions include the following types:

¡ (Required.) Output—The Output action forwards a packet to the specified OpenFlow port. OpenFlow switches must support forwarding packets to physical ports, logical ports, and reserved ports.

¡ (Required.) Drop—No explicit action exists to represent drops. Packets whose action sets have no output actions are dropped. Typically, packets are dropped due to empty instruction sets, empty action sets, or the executing a Clear-Actions instruction.

¡ (Required.) Group—Process the packet through the specified group. The exact interpretation depends on group type.

¡ (Optional.) Set-Queue—The Set-Queue action sets the queue ID for a packet. When the packet is forwarded to a port by the output action, the packet is assigned to the queue attached to this port for scheduling and forwarding. The forwarding behavior is dictated by the configuration of the queue and provides basic QoS support.

¡ (Optional.) Push-Tag/Pop-Tag—Switches support the ability to push or pop tags, such as VLAN tags, MPLS tags, and PBB tags.

¡ (Optional.) Set-Field—The Set-Field actions are identified by their field type and modify the values of corresponding header fields in the packet. Set-Field actions are always applied to the outermost header. For example, a Set VLAN ID action always sets the ID of the outermost VLAN tag.

¡ (Optional.) Change-TTL—The Change-TTL actions modify the values of the IPv4 TTL, IPv6 Hop Limit, or MPLS TTL in the packet. Change-TTL actions are always applied to the outermost header. The Change-TTL actions include the following the actions: Set TTL, Decrement TTL, and Copy TTL (outwards or inwards).

· Timeouts—Maximum amount of idle time or hard time for the flow entry.

¡ idle time—The flow entry is removed when it has matched no packets during the idle time.

¡ hard time—The flow entry is removed when the hard time timeout is exceeded, regardless of whether or not it has matched packets.

· Cookie—Custom data specified by the controller. The data are not used for processing packets, and might be used by the controller for matching flow entries.

· Flags—Flag for modifying the flow entry management method. For example, the OFPFF_SEND_FLOW_REM flag triggers the switch to send Flow-Removed messages for the flow entry to the controller.

Figure 2 Flow entry components

OpenFlow pipeline

The OpenFlow pipeline processing defines how packets interact with flow tables contained by a switch.

The flow tables of an OpenFlow switch are sequentially numbered, starting at 0. The packet is first matched with flow entries of the first flow table, which is flow table 0. A flow entry can only direct a packet to a flow table number that is greater than its own flow table number.

When a packet matches a flow entry, the OpenFlow switch updates the action set for the packet and passes the packet to the next flow table. In the last flow table, the OpenFlow switch executes all actions to modify packet contents and specify the output port for packet forwarding. If the instruction set of a flow table contains an action list, the OpenFlow switch immediately executes the actions for a copy of the packet in this table.

Figure 3 OpenFlow forwarding workflow

Table-miss flow entry

Every flow table must support a table-miss flow entry to process table misses. The table-miss flow entry specifies how to process packets that were not matched by other flow entries in the flow table.

The table-miss flow entry wildcards all match fields (all fields omitted) and has the lowest priority 0.

The table-miss flow entry behaves in most ways like any other flow entry.

Group table

The ability for a flow entry to point to a group enables OpenFlow to represent additional methods of forwarding. A group table contains group entries.

A group entry contains the following fields:

· Group Identifier—A 32 bit unsigned integer uniquely identifying the group.

· Group Type—Type of the group:

¡ All—Execute all buckets in the group. This group is used for multicast or broadcast forwarding.

¡ Select—Execute one bucket in the group.

¡ Indirect—Execute the one defined bucket in the group.

¡ Fast failover—Execute the first live bucket.

· 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.

Figure 4 Group entry components

Meter table

Meters enable OpenFlow to implement various simple QoS operations, such as rate-limiting. A meter table contains meter entries.

A meter entry contains the following fields:

· Meter Identifier—A 32 bit unsigned integer uniquely identifying the meter.

· Meter Bands—Each meter can have one or more meter bands. Each band specifies the rate at which the band applies and the way packets should be processed. If the current rate of packets exceeds the rate of multiple bands, the band with the highest configured rate is used.

· Counters—Updated when packets are processed by a meter.

Figure 5 Meter entry components

A meter band contains the following fields:

· Band Type—(Optional.) Packet processing methods. Options are:

¡ Drop—Discards the packet when the rate of the packet exceeds the band rate.

¡ DSCP Remark—Remarks the DSCP field in the IP header of the packet.

· Rate—Defines the lowest rate at which the band can apply.

· Counters—Updated when packets are processed by a band.

· Type Specific Arguments—Some band types have specific arguments.

Figure 6 Band components

OpenFlow channel

The OpenFlow channel is the interface that connects each OpenFlow switch to a controller. The controller uses the OpenFlow channel to exchange control messages with the switch to perform the following operations:

· Configure and manage the switch.

· Receive events from the switch.

· Send packets out the switch.

The OpenFlow channel is usually encrypted by using TLS. Also, an OpenFlow channel can be run directly over TCP.

The OpenFlow protocol supports the following message types: controller-to-switch, asynchronous, and symmetric. Each message type has its own subtypes.

Controller-to-switch messages

Controller-to-switch messages are initiated by the controller and used to directly manage or inspect the state of the switch. Controller-to-switch messages might or might not require a response from the switch.

The controller-to-switch messages include the following subtypes:

· Features—The controller requests the basic capabilities of a switch by sending a features request. The switch must respond with a features reply that specifies the basic capabilities of the switch.

· Configuration—The controller sets and queries configuration parameters in the switch. The switch only responds to a query from the controller.

· Modify-State—The controller sends Modify-State messages to manage state on the switches. Their primary purpose is to add, delete, and modify flow or group entries in the OpenFlow tables and to set switch port properties.

· Read-State—The controller sends Read-State messages to collect various information from the switch, such as current configuration and statistics.

· Packet-out—These are used by the controller to send packets out of the specified port on the switch, or to forward packets received through packet-in messages. Packet-out messages must contain a full packet or a buffer ID representing a packet stored in the switch. The message must also contain a list of actions to be applied in the order they are specified. An empty action list drops the packet.

· Barrier—Barrier messages are used to confirm the completion of the previous operations. The controller send s Barrier request. The switch must send a Barrier reply when all the previous operations are complete.

· Role-Request—Role-Request messages are used by the controller to set the role of its OpenFlow channel, or query that role. It is typically used when the switch connects to multiple controllers.

· Asynchronous-Configuration—These are used by the controller to set an additional filter on the asynchronous messages that it wants to receive, or to query that filter. It is typically used when the switch connects to multiple controllers.

Asynchronous messages

Switches send asynchronous messages to controllers to inform a packet arrival or switch state change. For example, when a flow entry is removed due to timeout, the switch sends a flow-removed message to inform the controller.

The asynchronous messages include the following subtypes:

· Packet-In—Transfer the control of a packet to the controller. For all packets forwarded to the Controller reserved port using a flow entry or the table-miss flow entry, a packet-in event is always sent to controllers. Other processing, such as TTL checking, can also generate packet-in events to send packets to the controller. The packet-in events can include the full packet or can be configured to buffer packets in the switch. If the packet-in event is configured to buffer packets, the packet-in events contain only some fraction of the packet header and a buffer ID. The controller processes the full packet or the combination of the packet header and the buffer ID. Then, the controller sends a packet-out message to direct the switch to process the packet.

· Flow-Removed—Inform the controller about the removal of a flow entry from a flow table. These are generated due to a controller flow delete request or the switch flow expiry process when one of the flow timeouts is exceeded.

· Port-status—Inform the controller of a state or setting change on a port.

· Error—Inform the controller of a problem or error.

Symmetric messages

Symmetric messages are sent without solicitation, in either direction.

The symmetric messages contain the following subtypes:

· Hello—Hello messages are exchanged between the switch and controller upon connection startup.

· Echo—Echo request or reply messages can be sent from either the switch or the controller, and must return an echo reply. They are mainly used to verify the liveness of a controller-switch connection, and might also be used to measure its latency or bandwidth.

· Experimenter—This is a staging area for features meant for future OpenFlow revisions.

OpenFlow timers

An OpenFlow switch supports the following timers:

· Connection detection interval—Interval at which the OpenFlow switch sends an Echo Request message to a controller. When the OpenFlow switch receives no Echo Reply message within three intervals, the OpenFlow switch is disconnected from the controller.

· Reconnection interval—Interval for the OpenFlow switch to wait before it attempts to reconnect to a controller.

OpenFlow controller

Controller roles

A switch can establish connections with multiple controllers. When OpenFlow operation is initiated, a switch is simultaneously connected to multiple controllers in Equal state. A controller can request its role to be changed at any time. The controller role contains the following types:

· Equal—In this role, the controller has full access to the switch and is equal to other controllers in the same role. By default, the controller receives all switch asynchronous messages such as packet-in and flow-removed messages. The controller can send controller-to-switch messages to modify the state of the switch.

· Master—This role is similar to the Equal role and has full access to the switch. The difference is that up to one controller in this role is allowed for a switch.

· Slave—In this role, the controller has read-only access to the switch.

The controller cannot send controller-to-switch messages to perform the following operations:

¡ Deploy flow entries, group entries, and meter entries.

¡ Modify the port and switch configurations.

¡ Send packet-out messages.

By default, the controller does not receive switch asynchronous messages except Port-status messages. The controller can send Asynchronous-Configuration messages to set the asynchronous message types it wants to receive.

Controller connection modes

An OpenFlow instance can connect to one or more controllers, depending on the controller connection mode the OpenFlow instance uses:

· Single—The OpenFlow instance connects to only one controller at a time. When communication with the current controller fails, the OpenFlow instance uses another controller.

· Multiple—The OpenFlow instance can simultaneously connect to multiple controllers. When communication with any controller fails, the OpenFlow instance attempts to reconnect to the controller after a reconnection interval.

Main and auxiliary connections

The OpenFlow channel can have one main connection and multiple auxiliary connections.

· Main connection—Processes control messages to complete operations such as deploying entries, obtaining data, and sending information. The main connection must be a reliable TCP or SSL connection.

· Auxiliary connection—Improves the communication performance between the controller and OpenFlow switches. An auxiliary connection can have the different destination IP address and port number than the main connection.

Connection interruption mode

When an OpenFlow switch is disconnected from all controllers, the OpenFlow switch is set to either of the following modes:

· Secure—The OpenFlow switch forwards traffic based on flow tables and does not remove unexpired flow entries. If the output action in a matching flow entry is to forward traffic to a controller, the traffic is discarded. This is the default forwarding mode.

· Standalone—The OpenFlow switch uses the normal forwarding process.

The OpenFlow switch forwards traffic based on flow tables when it reconnects to a controller successfully.

Protocols and standards

OpenFlow Switch Specification Version 1.3.3

OpenFlow tasks at a glance

To configure OpenFlow, perform the following tasks:

1. Configuring OpenFlow instances

a. Creating an OpenFlow instance

b. Configuring the OpenFlow instance mode

c. (Optional.) Configuring inband management VLANs

d. (Optional.) Configuring flow tables and flow entries for an OpenFlow instance

e. (Optional.) Setting the controller connection mode

f. (Optional.) Preventing an OpenFlow instance from reporting the specified types of ports to controllers

g. Activating or reactivating an OpenFlow instance

h. (Optional.) Configuring OpenFlow instance attributes

2. Configuring controllers for an OpenFlow switch

3. (Optional.) Configuring an OpenFlow instance to act as an SSL server to listen to controllers

Configuring OpenFlow instances

Creating an OpenFlow instance

1. Enter system view.

system-view

2. Create an OpenFlow instance and enter its view.

openflow instance instance-id

3. (Optional) Set the datapath ID.

datapath-id id

By default, the datapath ID of an OpenFlow instance contains the instance ID and the bridge MAC address of the device. The upper 16 bits are the instance ID and the lower 48 bits are the bridge MAC address of the device.

The datapath ID uniquely identifies an OpenFlow switch (OpenFlow instance). Do not set the same datapath ID for different OpenFlow switches.

Configuring the OpenFlow instance mode

Enabling the global mode for an OpenFlow instance

1. Enter system view.

system-view

2. Enter OpenFlow instance view.

openflow instance instance-id

3. Enable the global mode for the OpenFlow instance.

Classification global

By default, the OpenFlow instance mode is not configured.

Configuring inband management VLANs

About this task

Traffic in the inband management VLANs are forwarded in the normal forwarding process instead of the OpenFlow forwarding process. Inband management VLANs are used by an OpenFlow instance to establish OpenFlow channels to controllers.

Restrictions and guidelines

The ports that are assigned only to inband management VLANs are not OpenFlow ports.

If an OpenFlow instance in global mode connects to a controller through a non-management Ethernet interface, configure the VLAN to which the interface belongs as an inband management VLAN.

Procedure

1. Enter system view.

system-view

2. Enter OpenFlow instance view.

openflow instance instance-id

3. Configure inband management VLANs for the OpenFlow instance.

in-band management vlan { vlan-id [ to vlan-id ] } &<1-10>

By default, no inband management VLANs are configured for an OpenFlow instance.

Configuring flow tables and flow entries for an OpenFlow instance

Restrictions and guidelines

You can configure one MAC-IP flow table and one or more extensibility flow tables for an OpenFlow instance.

Procedure

1. Enter system view.

system-view

2. Enter OpenFlow instance view.

openflow instance instance-id

3. Configure flow tables for the OpenFlow instance.

flow-table { extensibility extensibility-table-id | mac-ip mac-ip-table-id }&<1-16>

By default, an OpenFlow instance contains one extensibility flow table with an ID of 0.

4. Set the maximum number of flow entries that each extensibility flow table supports.

flow-entry max-limit limit-value

By default, the maximum number of flow entries that each extensibility flow table supports is 65535.

When the maximum number is reached, the OpenFlow instance does not accept new flow entries for that table and sends a deployment failure notification to the controller.

When multiple extensibility flow tables exist, the limit applies to each extensibility flow table separately.

5. Configure the default action of table-miss flow entries to forward packets to the normal pipeline.

default table-miss permit

By default, the default action of table-miss flow entries is to drop packets.

For MPLS L3VPN packets to be correctly forwarded, configure this command when both MPLS L3VPN and OpenFlow are configured on the device.

Setting the controller connection mode

1. Enter system view.

system-view

2. Enter OpenFlow instance view.

openflow instance instance-id

3. Set the controller connection mode.

controller mode { multiple | single }

By default, the multiple mode is used.

Preventing an OpenFlow instance from reporting the specified types of ports to controllers

About this task

Perform this task to prevent an OpenFlow instance from reporting controllers information about the following types of interfaces that belong to the OpenFlow instance:

· VLAN interface.

· Virtual switch instance (VSI) interface.

Procedure

1. Enter system view.

system-view

2. Enter OpenFlow instance view

openflow instance instance-id

3. Prevent an OpenFlow instance from reporting the specified types of ports to controllers.

forbidden port { vlan-interface | vsi-interface } *

By default, no port types are prevented from being reported to the controllers. All ports that belong to an OpenFlow instance are reported to the controllers.

Activating or reactivating an OpenFlow instance

1. Enter system view.

system-view

2. Enter OpenFlow instance view.

openflow instance instance-id

3. Activate or reactivate the OpenFlow instance.

active instance

By default, an OpenFlow instance is not activated.

Configuring OpenFlow instance attributes

Restrictions and guidelines

The OpenFlow instance attribute configurations of an OpenFlow instance can take effect without activation for the OpenFlow instance.

Procedure

1. Enter system view.

system-view

2. Enter OpenFlow instance view.

openflow instance instance-id

3. Configure a description for the OpenFlow instance.

description text

By default, an OpenFlow instance does not have a description.

4. Set OpenFlow timers.

¡ Set the connection detection interval.

controller echo-request interval interval

The default setting is 5 seconds.

¡ Set the reconnection interval.

controller connect interval interval

The default setting is 60 seconds.

5. Configure MAC address-related features.

¡ Forbid MAC address learning for VLANs associated with the OpenFlow instance.

mac-learning forbidden

By default, MAC address learning is allowed for VLANs associated with an OpenFlow instance.

The configuration does not take effect on inband management VLANs.

¡ Configure the OpenFlow instance to support matching the dynamic MAC addresses in the query and deletion flow entry instructions sent from controllers.

mac-ip dynamic-mac aware

By default, an OpenFlow instance ignores dynamic MAC addresses in the query and deletion flow entry instructions sent from controllers.

Only MAC-IP flow tables support this feature.

Configuring controllers for an OpenFlow switch

Restrictions and guidelines

Make sure the configuration of an auxiliary connection does not conflict with the configuration of the main connection. Otherwise, the auxiliary connection cannot be established.

Procedure

1. Enter system view.

system-view

2. Enter OpenFlow instance view.

openflow instance instance-id

3. Specify a controller and configure the main connection to the controller.

controller controller-id address { ip ipv4-address | ipv6 ipv6-address } [ port port-number ] [ local address { ip local-ipv4-address | ipv6 local-ipv6-address } [ port local-port- number ] ] [ ssl ssl-policy-name ] [ vrf vrf-name ]

By default, an OpenFlow instance does not have a main connection to a controller.

The source IP address must be the IP address of a port belonging to an OpenFlow instance. Otherwise, the OpenFlow switch might fail to establish a connection with the controller.

4. (Optional) Specify a controller and configure an auxiliary connection to the controller.

controller id auxiliary auxiliary-id transport { tcp | udp | ssl ssl-policy-name } [ address { ip ipv4-address | ipv6 ipv6-address } ] [ port port-number ]

By default, an OpenFlow instance does not have auxiliary connections to a controller.

If no destination IP address and port number are specified, the auxiliary connection uses the destination IP address and port number configured for the main connection.

5. (Optional) Set the connection interruption mode.

fail-open mode { secure | standalone }

By default, the secure mode is used.

Configuring an OpenFlow instance to act as an SSL server to listen to controllers

About this task

Typically, an OpenFlow instance actively connects to the controller acting as a TCP/SSL client. After the SSL server is enabled for an OpenFlow instance, the controller acts as the SSL client and actively connects to the OpenFlow instance. For more information about SSL, see Security Configuration Guide.

Restrictions and guidelines

This feature can take effect without activation for an OpenFlow instance.

To re-configure the SSL server, first execute the undo form of the command to delete the existing SSL server configuration.

Procedure

1. Enter system view.

system-view

2. Enter OpenFlow instance view.

openflow instance instance-id

3. Configure an OpenFlow instance to act as an SSL server to listen to controllers.

listening port port-number ssl ssl-policy-name

By default, an OpenFlow instance is not configured to acts as an SSL server listen to controllers.

Display and maintenance commands for OpenFlow

Execute display commands in any view.

Task	Command
Display the detailed information for an OpenFlow instance.	display openflow instance [ instance-id ]
Display controller information for an OpenFlow instance.	display openflow instance instance-id { controller [ controller-id ] \| listened }
Display auxiliary connection information.	display openflow instance instance-id auxiliary [ controller-id [ auxiliary auxiliary-id ] ]
Display flow table entries for an OpenFlow instance.	display openflow instance instance-id flow-table [ table-id ]
Display group table information for an OpenFlow instance.	display openflow instance instance-id group [ group-id ]
Display meter table information for an OpenFlow instance.	display openflow instance instance-id meter [ meter-id ]
Display summary OpenFlow instance information.	display openflow summary
Clear statistics on packets that a controller sends and receives for an OpenFlow instance.	reset openflow instance instance-id { controller [ controller-id ] \| listened } statistics

OpenFlow configuration examples

Example: Configuring OpenFlow in global mode

Network configuration

As shown in Figure 7, perform the following tasks on the device:

· Create OpenFlow instance 1, assign all service interfaces on the device to the OpenFlow instance, and activate the OpenFlow instance.

· Specify the controller for OpenFlow instance 1 to manage the device.

Figure 7 Network diagram

Procedure

# Create OpenFlow instance 1 and configure it to operate in global mode.

[Device] openflow instance 1

[Device-of-inst-1] classification global

# Specify controller 1 for OpenFlow instance 1 and activate the instance.

[Device-of-inst-1] controller 1 address ip 192.168.49.49

[Device-of-inst-1] active instance

Verifying the configuration

# View detailed information about the OpenFlow instance.

[Device-of-inst-1] display openflow instance 1

Instance 1 information:

Configuration information:

Description : --

Active status : Active

Inactive configuration:

None

Active configuration:

Classification: Global(Standard)

...

Port information:

Route-Aggregation1

Active channel information:

Controller 1 IP address: 192.168.49.49 port: 6633

Appendix A Application restrictions

Flow entry restrictions

Matching restrictions

VLAN matching

Table 1 describes the VLAN matching restrictions when an OpenFlow instance is associated with VLANs.

Table 1 VLAN matching

VLAN	Mask	Matching packets
-	-	All packets in the VLANs that are associated the OpenFlow instance.
0	-	Packets without a VLAN tag. The PVID of the ingress port must be associated the OpenFlow instance.
0	Value	Unsupported.
Valid VLAN	-/value	Unsupported.
0x1000	-/value(except 0x1000)	Unsupported.
0x1000	0x1000	Packets with a VLAN tag. The VLAN ID of the VLAN tag must be associated with the OpenFlow instance.
Valid VLAN \| 0x1000	-/value	Matching packets by the combination of the VLAN ID and VLAN mask. The VLANs obtained through the combination of the VLAN ID and VLAN mask must be associated with the OpenFlow instance.
Other	Other	Unsupported.

Protocol packet matching

If protocols are enabled, protocol packets are processed by the corresponding protocols instead of the OpenFlow protocol.

The processing for LLDP frames is different. For more information about LLDP frame matching, see "LLDP frame matching."

Metadata matching

Metadata passes matching information between flow tables. The controller deploys metadata matching entries only to non-first flow tables. If the controller deploys a metadata matching entry to the first flow table, the switch returns an unsupported flow error.

Instruction restrictions

Table 2 Instruction restrictions

Instruction type	Restrictions
Clear-Actions	The Clear-Actions instruction has the following restrictions: · For the single flow table, the flow entries of the table cannot include this instruction and other instructions at the same time. · For multiple flow tables of the pipeline, only the flow entries of the first flow table can include this instruction and other instructions at the same time.
Apply-Actions	The action list of the Apply-Actions instruction cannot include multiple Output actions. When the action list includes only one Output action, the switch processes the action list as described in "Restrictions for merging the action list into the action set."
Write-Metadata/mask	The flow entries of the last table of the pipeline cannot include this instruction. Otherwise, the switch returns an unsupported flow error.
Goto-Table

Restrictions for merging the action list into the action set

The switch follows the following restrictions to merge the action list into the action set.

Non-output actions

When the action set and the action list do not contain the Output or Group action, the following rules apply:

· If actions in the action set do not conflict with actions in the action list, the switch merges the action list into the action set.

· If actions in the action set conflict with actions in the action list, actions in the action list are replaced with actions in the action set.

Output actions

When the action set and the action list contain the Output action or the Group action, the following rules apply:

· If both the action list and the action set contain an Output action, the Output action in the action list takes precedence. The Output action in the action list does not modify the packet. The Output action in the action set is executed at the last step of the pipeline processing to modify the packet.

· If either the action list or the action set contains an Output action, the port specified by the Output action is treated as the output port. The actions are executed in the order defined by the action set rules.

· If the action list contains an Output action and the action set contains a Group action, the following rules apply:

¡ The Output action does not modify the packet.

¡ The Group action is executed.

Packet-out messages restrictions

Ingress port

The ingress port must be a physical or logical port when one of the following reserved ports is the output port in a packet-out message:

· Normal.

· Local.

· In Port.

· Controller.

Buffer ID co-existing with packet

If a packet-out message contains both the packet and the buffer ID representing the packet stored in the switch, the switch processes only the buffered packet. The switch ignores the packet in the message.

Packets without a VLAN tag

If the packet contained in a packet-out message has no VLAN tag, the switch performs the following operations:

· Tags the packet with the PVID of the ingress port.

· Forwards the packet within the VLAN.

The switch processes the packet as follows when the ingress port is a reserved port:

· If the output port is a physical or logical port, the switch tags the packet with the PVID of the output port and forwards the packet within the VLAN.

· If the output port is the Flood or All reserved port, the switch processes the packet as described in "Output port."

Output port

If the output port in a packet-out message is the Flood or All reserved port, the switch processes the packet contained in the packet-out message as follows:

· When the output port is the Flood reserved port:

¡ If the packet has a VLAN tag, the switch broadcasts the packet within the VLAN.

¡ If the packet has no VLAN tag and the ingress port is a physical or logical port, the switch tags the packet with the PVID of the ingress port. The switch then forwards the packet within the VLAN.

¡ If the packet has no VLAN tag and the ingress port is the Controller reserved port, the switch forwards the packet out all OpenFlow ports.

· When the output port is the All reserved port:

¡ If the packet has a VLAN tag, the switch broadcasts the packet within the VLAN.

¡ If the packet has no VLAN tag, the switch forwards the packet out of all OpenFlow ports regardless of the ingress port type.

Packet-in messages restrictions

Processing VLAN tags

When sending a packet-in message to the controller, the switch processes the VLAN tag of the packet contained in the packet-out message as follows:

· If the VLAN tag of the packet is the same as the PVID of the ingress port, the switch removes the VLAN tag.

· If the VLAN tag of the packet is different from the PVID of the ingress port, the switch does not remove the VLAN tag.

Packet buffer

If a packet-in message is sent to controller due to no matching flow entry, the switch supports buffering the packet contained in the packet-in message. The buffer size is 1K packets.

If a packet-in message is sent to controller for other reasons, the switch does not support buffering the packet contained in the packet-in message. The switch must send the full packet to the controller, and the cookie field of the packet is set to 0xFFFFFFFFFFFFFFFF.

LLDP frame matching

LLDP is used to perform topology discovery in an OpenFlow network. LLDP must be enabled globally on a device. A switch sends a LLDP frame to the controller through the packet-in message when the following conditions exist:

· The port that receives the LLDP frame from the controller belongs to OpenFlow instances.

· The flow tables in the OpenFlow instance have a flow entry that matches the LLDP frame (the output port is the Controller reserved port).

Flow table modification messages restrictions

The flow table modification messages have the following restrictions for the table-miss flow entry and common flow entries.

Table-miss flow entry

The controller deploys the table-miss flow entry (the action is Drop) to an OpenFlow instance after the OpenFlow instance is activated.

The controller cannot query the table-miss flow entry through Multipart messages.

The controller cannot modify the table-miss flow entry through the Modify request. The controller can only modify the table-miss flow entry through the Add request.

The controller can modify or delete the table-miss flow entry only through the strict version of the Modify or Delete request. The controller cannot modify or remove the table-miss flow entry through the non-strict version of the Modify or Delete request despite that the match fields are wildcarded.

The controller deploys a table-miss flow entry (the action is Drop) to an OpenFlow instance after the current table-miss flow entry is deleted.

Common flow entries

The controller cannot modify or remove all common flow entries through the non-strict version of the Modify or Delete request despite that the match fields are wildcarded.

Appendix B MAC-IP flow table

Capabilities supported by the MAC-IP flow table

The controller must include the required match fields and actions and can include the optional match fields and actions in the flow entries deployed to the MAC-IP flow table. If the controller does not include the optional match fields and actions in the flow entries, the switch adds them to the flow entries by default.

The Layer 2 flow entries are implemented by using MAC address entries. Table 3 describes the capabilities supported by Layer 2 flow entries.

Table 3 Capabilities supported by Layer 2 flow entries

Item	Capabilities
Required match fields	The MAC-IP flow table must support the following match fields: · VLAN ID. · Unicast destination MAC address.
Optional match fields	N/A
Required actions	Specifying the output port.
Optional actions	The MAC-IP flow table can optionally support the following instructions: · Goto-Table—When the switch has multiple tables, the switch adds this instruction by default if the controller does not deploy it. · Write-Metadata—When the switch has multiple tables, the switch adds this instruction by default if the controller does not deploy it.

The Layer 3 flow entries are implemented by using routing entries. Table 4 describes the capabilities supported by Layer 3 flow entries.

Table 4 Capabilities supported by Layer 3 flow entries

Item	Capabilities
Required match fields	The MAC-IP flow table must support the following match fields: · VLAN ID. · Ethernet type. · Unicast destination IP address. · Unicast destination MAC address, which must be the MAC address of the VLAN interface for the VLAN that is matched.
Optional match fields	N/A
Required actions	Specifying the output port.
Optional actions	The MAC-IP flow table can optionally support the following actions: · Modify source MAC address—The switch modifies the source MAC address to the MAC address of the VLAN interface for the VLAN to which the output port belongs. · Decrement TTL by one. · Goto-Table—When the switch has multiple tables, the switch adds this instruction by default if the controller does not deploy it. · Write-Metadata—When the switch has multiple tables, the switch adds this instruction by default if the controller does not deploy it.

The VXLAN Layer 2 flow entries are implemented by using MAC address entries. Table 5 describes the capabilities supported by VXLAN Layer 2 flow entries.

Table 5 Capabilities supported by VXLAN Layer 2 flow entries

Item	Capabilities
Required match fields	Unicast destination MAC address.
Optional match fields	N/A
Required actions	The MAC-IP flow table must support the following actions: · Specifying a tunnel interface as the output port. · Specifying the tunnel ID.
Optional actions	The MAC-IP flow table can optionally support the following instructions: · Goto-Table—When the switch has multiple tables, the switch adds this instruction by default if the controller does not deploy it. · Write-Metadata—When the switch has multiple tables, the switch adds this instruction by default if the controller does not deploy it.

The VXLAN Layer 3 flow entries are implemented by using routing entries. Table 6 describes the capabilities supported by VXLAN Layer 3 flow entries.

Table 6 Capabilities supported by VXLAN Layer 3 flow entries

Item	Capabilities
Required match fields	The MAC-IP flow table must support the following match fields: · Ethernet type. · Unicast destination IP address.
Optional match fields	N/A
Required actions	The MAC-IP flow table must support the following actions: · Specifying a tunnel interface as the output port. · Specifying the tunnel ID. · Modifying the destination MAC address.
Optional actions	The MAC-IP flow table can optionally support the following actions: · Goto-Table—When the switch has multiple tables, the switch adds this instruction by default if the controller does not deploy it. · Write-Metadata—When the switch has multiple tables, the switch adds this instruction by default if the controller does not deploy it.

MAC-IP flow table restrictions

Controller must follow the restrictions in the following tables to deploy flow entries for MAC-IP flow table. Otherwise, forwarding failure might occur.

Table 7 Restrictions for deploying Layer 2 flow entries for the MAC-IP flow table

Item	Restrictions
Match fields	The destination MAC address cannot be the MAC address of the switch to which the flow entry is deployed.
Actions	The output port must belong to the VLAN that is matched.

Table 8 Restrictions for deploying Layer 3 flow entries for the MAC-IP flow table

Item	Restrictions
Match fields	The VLAN interface of the VLAN that is matched is in up state. The destination MAC address is the MAC address of the VLAN interface for the VLAN that is matched. The destination IP address cannot be the IP address of the switch to which the flow entry is deployed.
Actions	The specified output port must belong to the destination VLAN. The destination MAC address cannot be the MAC address of the switch to which the flow entry is deployed. If the switch modifies the source MAC address, the source MAC address must be the MAC address of the VLAN interface for the VLAN to which the output port belongs.

Item

Restrictions

Match fields

The VLAN interface of the VLAN that is matched is in up state.

The destination MAC address is the MAC address of the VLAN interface for the VLAN that is matched.

The destination IP address cannot be the IP address of the switch to which the flow entry is deployed.

Actions

The specified output port must belong to the destination VLAN.

The destination MAC address cannot be the MAC address of the switch to which the flow entry is deployed.

If the switch modifies the source MAC address, the source MAC address must be the MAC address of the VLAN interface for the VLAN to which the output port belongs.

To deploy a Layer 3 flow entry, make sure the following requirements are met:

· The VLAN interface of the matched VLAN is in up state.

· The switch sends the controller a packet that indicates the VLAN interface acts as an OpenFlow port. The link state and the MAC address of the VLAN interface are also included in the packet.

The switch reports the VLAN interface deletion to the controller and the controller removes the corresponding Layer 3 flow entry.

The controller ensures the correctness of Layer 3 flow entries. The switch does not check for the restrictions for Lay 3 flow entries.

Table 9 Restrictions for deploying VXLAN Layer 2 flow entries for the MAC-IP flow table

Item	Restrictions
Match fields	The destination MAC address cannot be MAC address of the switch to which the flow entry is deployed.
Actions	The output port must be an existing tunnel interface. The VXLAN that corresponds to the specified tunnel ID (VNI) must exist.

Item

Restrictions

Match fields

The destination MAC address cannot be MAC address of the switch to which the flow entry is deployed.

Actions

The output port must be an existing tunnel interface.

The VXLAN that corresponds to the specified tunnel ID (VNI) must exist.

‌

Table 10 Restrictions for deploying VXLAN Layer 3 flow entries for the MAC-IP flow table

Item	Restrictions
Match fields	The destination IP address cannot be the IP address of the switch to which the flow entry is deployed.
Actions	The output port must be an existing tunnel interface. The VXLAN and the VSI interface that correspond to the specified tunnel ID (VNI) must exist. The destination MAC address cannot be MAC address of the switch to which the flow entry is deployed.

Item

Restrictions

Match fields

The destination IP address cannot be the IP address of the switch to which the flow entry is deployed.

Actions

The output port must be an existing tunnel interface.

The VXLAN and the VSI interface that correspond to the specified tunnel ID (VNI) must exist.

The destination MAC address cannot be MAC address of the switch to which the flow entry is deployed.

‌

Table-miss flow entry of MAC-IP flow tables

The table-miss flow entry of a MAC-IP flow table supports the following output actions:

· Goto-Table—Direct the packet to the next table.

· Drop—Drop the packet.

· Controller—Send the packet to the controller.

· Normal—Forward the packet to the normal pipeline.

Dynamic aware

On an OpenFlow switch that supports MAC-IP flow tables, you can configure OpenFlow to support querying and deleting dynamic MAC address flow entries.

The controller can query and delete dynamic MAC address flow entries by specifying a VLAN, a MAC address, or the combination of a MAC address and a VLAN.

MAC-IP flow table cooperating with extensibility flow table

Metadata/mask

The MAC-IP flow table supports the Write Metadata/mask instruction and the extensibility flow table supports metadata/mask matching. The MAC-IP flow table can cooperate with an extensibility flow table to perform the pipeline process of multiple tables by using metadata/mask.

Each metadata mask bit has a different meaning. The corresponding metadata bit being set indicates that the metadata mask bit is matched. When the corresponding metadata bit is not set, the metadata mask bit is wildcarded.

Table 11 Metadata mask meanings

Metadata mask bit	Meaning	Metadata
Bit 0	Destination MAC address	· 1—Set. Matches the destination MAC address. · 0—Not set. Does not match the destination MAC address.
Bit 1	Source MAC address	· 1—Set. Matches the source MAC address. · 0—Not set. Does not match the source MAC address.
Bit 2	Destination IP address	· 1—Set. Matches the destination IP address. · 0—Not set. Does not match the destination IP address.
Others	Reserved	Reserved.

Matching restrictions

When the output action in an extensibility flow table is not Normal, the following rules apply:

· The MAC-IP flow table does not take effect.

· All actions are executed according to the extensibility flow table.

When the output action in an extensibility flow table is Normal, the following rules apply:

· The output action is executed according to the MAC-IP flow table.

· The other actions are executed according to the extensibility flow table.

14-OpenFlow Configuration Guide

OpenFlow instance mode

Activation and reactivation

OpenFlow instance port

Flow table types

Flow entry

OpenFlow pipeline

Table-miss flow entry

Controller-to-switch messages

Asynchronous messages

Symmetric messages

OpenFlow timers

Controller roles

Controller connection modes

Main and auxiliary connections

Connection interruption mode

Enabling the global mode for an OpenFlow instance

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Restrictions and guidelines

Procedure

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Procedure

Setting the controller connection mode

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Procedure

Restrictions and guidelines

Procedure

Restrictions and guidelines

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Restrictions and guidelines

Procedure

Network configuration

Procedure

Verifying the configuration

Matching restrictions

VLAN matching

Protocol packet matching

Metadata matching

Instruction restrictions

Non-output actions

Output actions

Ingress port

Buffer ID co-existing with packet

Packets without a VLAN tag

Processing VLAN tags

Packet buffer

Table-miss flow entry

Common flow entries

Appendix B MAC-IP flow table

Metadata/mask

Matching restrictions

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