Ethernet Virtual Connections on Port Channels

A port channel bundles individual Ethernet links into a single logical link that provides an aggregated bandwidth of up to four physical links. The Ethernet Virtual Connection (EVC) Port Channel feature provides support for the Ethernet service instances on a port channel.

Information About Ethernet Virtual Connections on Port Channels

Usage Guidelines for Configuring an EVC on a Port Channel

Prior to configuring an EVC on a port channel, consider these usage guidelines:

  • All the member links of the port channel are on the Cisco ASR 1000 Fixed Ethernet Line card or on the shared port adapters (SPAs).

  • All the member links of the port channel must be configured such that they are of the same speed, and are in the same duplex mode.

  • EVC connect and IP subinterfaces are allowed to co-exist over the port-channel interface.

  • If you configure a physical port as part of a channel group, you cannot configure EVCs under that physical port.

  • You cannot use the bandwidth percent or police percent commands on EVC port channels in flat policy maps or in the parent of the Hierarchical quality of service (HQoS) policy maps.

Quality of Service Support

The following Quality of Service (QoS) policy settings are supported for egress traffic on the Cisco ASR 1000 Layer 3 port-channel interface:

  • The QoS on the subinterface of a port channel with a specific encapsulation, such as, VLAN.

  • The QoS on a member link.

  • Modular QoS CLI (MQC) policy aggregation is supported with VLAN-based load balancing on subinterfaces and member-link ports.

The following section describes the QoS support for the following interfaces:

Port-Channel Interface

  • Does not support any QoS policies on the port-channel interface.

Member-Link Interface

  • Supports egress queuing, policing, and marking for flow-based load balancing.

  • Supports egress queuing, policing, and marking for VLAN-based manual load balancing.

  • Supports egress queuing, policing, marking, and the configuration of similar policies on two links for LACP 1:1.

EVC on Port-Channel Interface

  • Does not support flow-based load balancing.

  • Supports ingress and egress policing and marking for VLAN-based manual load balancing.

  • Supports ingress and egress policing and marking for LACP 1:1.


Note

Ensure that you configure the QoS policies for the EVCs on a port channel and a member link separately.


Note

Service policies for ingress traffic are supported on EVC only.

Configuring a Basic EVC Port Channel

Configuring a Port Channel Interface with ethernet Service Instances

To configure a port-channel interface with Ethernet service instances, perform the following steps.

SUMMARY STEPS

  1. enable
  2. configure terminal
  3. interface port-channel number
  4. [no] ip address
  5. no negotiation auto
  6. [no] service instance id Ethernet [ service-name]
  7. encapsulation { default | untagged | dot1q vlan-id [ second-dot1q vlan-id] }
  8. [no] service instance id ethernet [ service-name]
  9. encapsulation {default | untagged | dot1q vlan-id [ second-dot1q vlan-id] }

DETAILED STEPS

  Command or Action Purpose
Step 1

enable

Example:

Router# enable

Enables the privileged EXEC mode. Enter your password if prompted.

Step 2

configure terminal

Example:

Router# configure terminal

Enters the global configuration mode.

Step 3

interface port-channel number

Example:

Router(config)# interface port-channel 11

Creates the port-channel interface.

Step 4

[no] ip address

Example:

Router(config-if)# no ip address

Removes an IP address or disables IP processing.

Step 5

no negotiation auto

Example:

Router(config-if)# no negotiation auto

Disables the advertisement of speed, duplex mode, and flow control on a Gigabit Ethernet interface.

Step 6

[no] service instance id Ethernet [ service-name]

Example:

Router(config-if)# service instance 1 ethernet

Creates a service instance (an instantiation of an EVC) on an interface and sets the device to the config-if-srv submode.

Step 7

encapsulation { default | untagged | dot1q vlan-id [ second-dot1q vlan-id] }

Example:

Router(config-if-srv)# encapsulation dot1q 101

Defines the matching criteria to be used in order to map ingress dot1q frames on an interface to the appropriate service instance.

Step 8

[no] service instance id ethernet [ service-name]

Example:

Router(config-if)# service instance 2 ethernet

Creates a second service instance on the interface.

Step 9

encapsulation {default | untagged | dot1q vlan-id [ second-dot1q vlan-id] }

Example:

Router(config-if-srv)# encapsulation dot1q 201

Defines the matching criteria to be used in order to map ingress dot1q frames on an interface to the appropriate service instance.

Adding a Port Channel Ethernet Flow Point to a Bridge Domain

To add a port channel Ethernet Flow Point (EFP) to a bridge domain, perform the following steps.

SUMMARY STEPS

  1. [no] bridge-domain bridge-id
  2. member port-channel interface id service-instance id
  3. [no] bridge-domain bridge-id | xconnect vfi vfi name
  4. member port-channel interface id service-instance id

DETAILED STEPS

  Command or Action Purpose
Step 1

[no] bridge-domain bridge-id

Example:

Router(config-if-srv)# bridge-domain 100

The bridge-domain command binds the service instance to a bridge domain instance, where bridge-id is the identifier of the bridge-domain instance. To disable bridging, use the no form of this command.

Step 2

member port-channel interface id service-instance id

Example:

Router(config-if-srv)# member Port-channel1 service-instance 1

Creates a service instance on the interface.

Step 3

[no] bridge-domain bridge-id | xconnect vfi vfi name

Example:

Router(config-if-srv)# bridge-domain 200

The bridge-domain command binds the service instance to a bridge-domain instance, where bridge-id is the identifier of the bridge-domain instance. The xconnect vfi command specifies the Layer 2 virtual forwarding interface (VFI) that you are binding to the interface, where vfi name is the name of the VFI.

Step 4

member port-channel interface id service-instance id

Example:

Router(config-if-srv)# member Port-channel1 service-instance 2

Creates a service instance on the interface.

Adding an Ethernet Port to the Port Channel Interface

To configure the channel group number on the Ethernet port and to add an Ethernet port to the port-channel interface, perform the following steps.

SUMMARY STEPS

  1. interface GigabitEthernet slot/port/sub-port
  2. no ip address
  3. no negotiation auto
  4. channel-group channel-group-number
  5. end

DETAILED STEPS

  Command or Action Purpose
Step 1

interface GigabitEthernet slot/port/sub-port

Example:

Router(config-if-srv)# interface GigabitEthernet0/2/0

Specifies the Gigabit Ethernet port that is to be configured. This is the port in which the slot, port, or subport specifies the location of the Gigabit Ethernet port.

Step 2

no ip address

Example:

Router(config-if-srv)# no ip address

Removes an IP address or disables IP processing.

Step 3

no negotiation auto

Example:

Router(config-if-srv)# no negotiation auto

Disables the advertisement of speed, duplex mode, and flow control on a Gigabit Ethernet interface.

Step 4

channel-group channel-group-number

Example:

Router(config-if-srv)# channel-group 1

Assigns a port-channel interface to a port-channel group.

Step 5

end

Example:

Router(config-if-srv)# end

Exits the command-line interface and enters the privileged EXEC mode.

Load Balancing the EVCs on Port Channels

The load balancing of the EVCs in a port channel aims to load balance traffic across the member links of that port channel when the EVCs are configured. In the VLAN-based load-balancing method, if you do not assign EVCs to a member link, they will be statically mapped to one of the active port-channel member links, which will result in the outgoing traffic being limited to the bandwidth of the member link. In the flow-based load-balancing method, the traffic is distributed across all member links.

EFPs are configured under a port channel. The traffic, which is carried by the EFPs, is load balanced across member links. Ingress traffic for a single EVC can arrive on any member of the bundle. All the egress traffic pertaining to an EFP uses only one of the member links. Load balancing is achieved by grouping EFPs and assigning them to a member link. The Cisco ASR 1000 Layer 2 port-channel interface supports flow-based load balancing by default. In default load balancing, you have no control over how the EFPs are grouped together, and sometimes, the EFP grouping may not be ideal. To avoid this, use VLAN-based manual load balancing to control the EFP grouping.

Flow-Based Load Balancing

Flow-based load balancing is the default load-balancing method that is applied on a specific system level or a specific port channel level. However, EVC port channel also supports the VLAN-based load-balancing method. You can configure either of the load balancing methods globally for all the port channels or directly on specific port channels.

Load-Balancing Algorithm

When you select flow-based load balancing, a global flow-based load-balancing algorithm is applied to the port channel by default. Using the packet header information, the corresponding port channel balances the traffic across all the member links. You can configure the device to use one of the following methods to load balance across the port channels:

  • Destination IP Address

  • Destination MAC Address

  • Source exclusive OR (XOR) Destination IP Address

  • Source XOR Destination MAC Address

  • Source IP Address

  • Source MAC Address

The provision that you configure will be applied to all the egress traffic streams on all the port-channel interfaces that have flow-based load balancing.

The following is a sample configuration of the flow-based load-balancing algorithm: 


Router(config)# port-channel load-balance-hash-algo ?
dst-ip Destination IP
dst-mac Destination MAC
src-dst-ip Source XOR Destination IP Addr
src-dst-mac Source XOR Destination MAC
src-ip Source IP
src-mac Source MAC


Note

Flow-based load balancing is enabled by default at the global level. You must explicitly configure VLAN-based load balancing; otherwise, the default load-balancing method is flow-based.

To enable flow-based load balancing on a port channel, perform the following steps:

SUMMARY STEPS

  1. enable
  2. configure terminal
  3. interface port-channel port-channel number
  4. load-balancing {flow | vlan}
  5. end

DETAILED STEPS

  Command or Action Purpose
Step 1

enable

Example:

Router# enable

Enables the privileged EXEC mode.

Step 2

configure terminal

Example:

Router# configure terminal

Enters the global configuration mode.

Step 3

interface port-channel port-channel number

Example:

Router(config)# interface port-channel 1

Specifies the port channel to configure, and enters the configuration mode.

Step 4

load-balancing {flow | vlan}

Example:

Router(config-if)# load-balancing flow

Applies the load-balancing method to the specific port channel.

Step 5

end

Example:

Router(config-if)# end

Exits the configuration mode.

Configuring Flow Based Load Balancing

To configure flow-based load balancing on an EVC port channel, perform the following steps.

SUMMARY STEPS

  1. enable
  2. configure terminal
  3. interface port-channel channel-number
  4. port-channel load-balance flow-based
  5. end

DETAILED STEPS

  Command or Action Purpose
Step 1

enable

Example:

Router# enable

Enables the privileged EXEC mode. Enter your password if prompted.

Step 2

configure terminal

Example:

Router# configure terminal

Enters the global configuration mode.

Step 3

interface port-channel channel-number

Example:

Router(config)# interface port-channel 1

Creates the port-channel interface.

Step 4

port-channel load-balance flow-based

Example:

Router(config-if)# port-channel load-balance flow-based

Configures the specified port-channel interface in the flow-based load-balancing mode.

Step 5

end

Exits the configuration mode.

VLAN-Based Manual Load Balancing

Configuring VLAN Based Manual Load Balancing

Perform this task to link a VLAN port channel, and to enable VLAN load balancing on port channels:

SUMMARY STEPS

  1. enable
  2. configure terminal
  3. interface port-channel channel-number
  4. no ip address
  5. no negotiation auto
  6. port-channel load-balancing link 1
  7. backup link 2
  8. service-instance 100,300
  9. port-channel load-balancing link 2
  10. backup link 1
  11. service-instance 200,400
  12. load-balancing vlan
  13. service instance id ethernet
  14. encapsulation { default | untagged | dot1q vlan-id [ second-dot1q vlan-id] }
  15. service instance id ethernet
  16. encapsulation { default | untagged | dot1q vlan-id [ second-dot1q vlan-id] }
  17. service instance id ethernet
  18. encapsulation { default | untagged | dot1q vlan-id [ second-dot1q vlan-id] }
  19. service instance id ethernet
  20. encapsulation { default | untagged | dot1q vlan-id [ second-dot1q vlan-id] }
  21. interface type number
  22. no ip address
  23. no negotiation auto
  24. channel-group channel-number link link-number
  25. interface type number
  26. no ip address
  27. no negotiation auto
  28. channel-group channel-number link link-number
  29. end

DETAILED STEPS

  Command or Action Purpose
Step 1

enable

Example:

Router> enable

Enables the privileged EXEC mode.

Enter your password if prompted.

Step 2

configure terminal

Example:

Router# configure terminal

Enters the global configuration mode.

Step 3

interface port-channel channel-number

Example:

Router(config)# interface port-channel 1

Enters the interface configuration mode and defines the interface as a port channel.

Step 4

no ip address

Example:

Router(config-if)# no ip address

Removes an IP address or disables IP processing.

Step 5

no negotiation auto

Example:

Router(config-if)# no negotiation auto

Disables the advertisement of speed, duplex mode, and flow control on a port-channel interface.

Step 6

port-channel load-balancing link 1

Example:

Router(config-if)# port-channel load-balancing link 1

Enables port-channel load balancing on link 1.

Step 7

backup link 2

Example:

Router(config-if)# backup link 2

Assigns a backup link 2.

Step 8

service-instance 100,300

Example:

Router(config-if)# service-instance 100,300

Creates a service instance on the interface.

Step 9

port-channel load-balancing link 2

Example:

Router(config-if)# port-channel load-balancing link 2

Enables port-channel load balancing on link 2.

Step 10

backup link 1

Example:

Router(config-if)# backup link 1

Assigns a backup link 1.

Step 11

service-instance 200,400

Example:

Router(config-if)# service-instance 200,400

Creates a service instance on the interface.

Step 12

load-balancing vlan

Example:

Router(config-if)# load-balancing vlan

Enables port-channel load balancing on the router.

Step 13

service instance id ethernet

Example:

Router(config-if)# service instance 100 ethernet

Creates a service instance on the interface.

Step 14

encapsulation { default | untagged | dot1q vlan-id [ second-dot1q vlan-id] }

Example:

Router(config-if-srv)# encapsulation dot1q 100

Defines the matching criteria to be used in order to map the ingress dot1q frames on an interface to the appropriate service instance.

Step 15

service instance id ethernet

Example:

Router(config-if)# service instance 200 ethernet

Creates a service instance on the interface.

Step 16

encapsulation { default | untagged | dot1q vlan-id [ second-dot1q vlan-id] }

Example:

Router(config-if-srv)# encapsulation dot1q 200

Defines the matching criteria to be used in order to map the ingress dot1q frames on an interface to the appropriate service instance.

Step 17

service instance id ethernet

Example:

Router(config-if)# service instance 300 ethernet

Creates a service instance on the interface.

Step 18

encapsulation { default | untagged | dot1q vlan-id [ second-dot1q vlan-id] }

Example:

Router(config-if-srv)# encapsulation dot1q 300

Defines the matching criteria to be used in order to map the ingress dot1q frames on an interface to the appropriate service instance.

Step 19

service instance id ethernet

Example:

Router(config-if)# service instance 400 ethernet

Creates a service instance on the interface.

Step 20

encapsulation { default | untagged | dot1q vlan-id [ second-dot1q vlan-id] }

Example:

Router(config-if-srv)# encapsulation dot1q 400

Defines the matching criteria to be used in order to map the ingress dot1q frames on an interface to the appropriate service instance.

Step 21

interface type number

Example:

Router(config)# interface gigabitethernet0/2/6

Specifies the interface type and number.

Step 22

no ip address

Example:

Router(config-if)# no ip address

Removes an IP address or disables IP processing.

Step 23

no negotiation auto

Example:

Router(config-if)# no negotiation auto

Disables the advertisement of speed, duplex mode, and flow control on a port-channel interface.

Step 24

channel-group channel-number link link-number

Example:

Router(config-if)# channel-group 1 link 1

Assigns a Gigabit Ethernet interface to the specified channel group and link.

Step 25

interface type number

Example:

Router(config)# interface gigabitethernet0/2/7

Specifies the interface type and number.

Step 26

no ip address

Example:

Router(config-if)# no ip address

Removes an IP address or disables IP processing.

Step 27

no negotiation auto

Example:

Router(config-if)# no negotiation auto

Disables the advertisement of speed, duplex mode, and flow control on a port-channel interface.

Step 28

channel-group channel-number link link-number

Example:

Router(config-if)# channel-group 1 link 1

Assigns a Gigabit Ethernet interface to the specified channel group and link.

Step 29

end

Example:

Router(config-if)# end

Exits the interface configuration mode, and returns to the privileged EXEC mode.

Example: Ethernet Virtual Connections on Port Channels

Example: Ethernet Virtual Connections on Port Channels

The following example shows how to configure flow-based load balancing on a port-channel interface: 



Router# enable
Router# configure terminal
Router(config)# interface Port-channel 1
Router(config-if)# port-channel load-balance flow-based
Router(config-if)# end

The following example shows how to configure QoS on an EVC port channel: 



Router> enable
Router# configure terminal
Router(config)# class-map c1-cos2-cos4
match cos 2 match vlan 1
Router(config)# policy-map p1-ingress
Router(config-pmap)# class c1-cos2-cos4
Router(config-pmap-c)# police cir 100000 conform-action set-cos-transmit 4
Router(config)# interface Port-channel1
Router(config-if)# no ip address
Router(config-if)# no negotiation auto
Router(config-f)# load-balancing vlan
Router(config-if)# service instance 1 ethernet
Router(config-if-srv)# encapsulation dot1q 1
Router(config-if-srv)# service-policy input p1-ingress
Router(config-if)# port-channel load-balance link 1
Router(config-if)# backup link 2
Router(config-if)# service-instance 1
Router(config-if)# interface GigabitEthernet3/0/3
Router(config-if)# no ip address
Router(config-if)# no shutdown
Router(config-if)# negotiation auto
Router(config-if)# channel-group 1 link 1
Router(config-if)# interface GigabitEthernet5/0/0
Router(config-if)# no ip address
Router(config-if)# no shutdown
Router(config-if)# negotiation auto
Router(config-if)# channel-group 1 link 2
Router(config-if)# bridge-domain 1
Router(config-if)# member Port-channel1 service-instance 1

The following example shows how to use the show running-config interface port-channel channel-number command to verify an EVC port channel's per-flow load-balancing configuration: 



Router# enable
Router# configure terminal
Router(config)# interface Port-channel 2
Router(config-if)# port-channel load-balance flow-based
Router(config-if)# end
Router# show running-config interface Port-channel 2

Building configuration...
Current configuration : 113 bytes
! 
interface Port-channel2
band width 1000000
no ip address
 port-channel load-balance flow-based
end

Configuring LACP

To configure the channel mode for each individual link in the LACP port channel, perform the following steps.

SUMMARY STEPS

  1. config t
  2. interface type slot/port
  3. channel-group number mode {active | on | passive}
  4. lacp {port-priority | rate}

DETAILED STEPS

  Command or Action Purpose
Step 1

config t

Example:

Router# config t
Router(config)#

Enters the configuration mode.

Step 2

interface type slot/port

Example:

Router(config)# interface GigabitEthernet0/2/0

Specifies the interface to configure, and enters the interface configuration mode.

Step 3

channel-group number mode {active | on | passive}

Example:

Router(config-if)# channel-group 1 mode active

Specifies the port mode for the link in a port channel. After the LACP is enabled, configure each link or the entire channel as active or passive. When you run port channels with no associated aggregation protocol, the port channel mode is always on.

Step 4

lacp {port-priority | rate}

Example:

Router(config-if)# lacp port-priority 4000

Configures the port priority for use with the LACP.

Configuring the LACP Mode per Port Channel Interface

To configure the LACP mode on an individual port-channel interface, perform the following steps.

SUMMARY STEPS

  1. interface port-channel port-channel number
  2. lacp {fast switch-over | max-bundle | min-bundle}

DETAILED STEPS

  Command or Action Purpose
Step 1

interface port-channel port-channel number

Example:

Router(config)# interface port-channel 1

Specifies the port channel to configure, and enters the configuration mode.

Step 2

lacp {fast switch-over | max-bundle | min-bundle}

Example:

Router (config-int)# lacp max-bundle 4

max-bundle -Specifies the maximum number of ports to bundle in this port channel.

fast switch-over -Enables fast switchover on this port channel.

min-bundle -Specifies the minimum number of ports to bundle in this port channel.

Configures four active links on the port channel. The remaining links are in standby mode. Traffic is load-balanced among the active links.