Carrier Ethernet Configuration Guide, Cisco IOS XE Release 3S (Cisco ASR 900 Series)
Trunk EFP Support
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Trunk EFP Support

Trunk EFP Support

The Trunk EFP Support feature provides support for Ethernet flow points (EFPs) on trunk ports. A trunk port allows a range of VLANs to be forwarded on a given interface while still maintaining data-plane segmentation between the VLANs.

Restrictions for Trunk EFP Support

  • The rewrite ingress tag pop 1 symmetric command is the only rewrite command that is supported for trunk EFP configurations. The rewrite ingress tag pop 1 symmetric command must be included in the configuration when the Trunk EFP Support feature is enabled.
  • A bridge-domain number that is part of a trunk EFP configuration cannot be shared by other EFPs under the same port or interface.
  • Only one trunk EFP can be configured under one port or interface.
  • All features configured on a trunk EFP (other than encapsulations and bridge-domain assignments) are applied uniformly to all VLANs and bridge domains. If a feature requires VLAN-specific or bridge-domain-specific configuration values, the feature cannot be applied on the trunk EFP. Those special VLANs or bridge domains must be removed from the EFP trunk to form individual EFPs.

Restrictions for Trunk EFP Support on Cisco ASR 903 Routers

  • Only 1000 VLANs can be configured for a trunk EFP (with or without port channel).

Information About Trunk EFP Support

Benefits of Trunk EFP Support

The Carrier Ethernet infrastructure supports the following types of Ethernet flow points (EFPs):
  • Static EFPs that are user-configurable.
  • Dynamic EFPs that are created and maintained during a Cisco Intelligent Services Gateway ( ISG) session.

With this feature, a new EFP type has been added that is intended for use on a trunk port.

A trunk port allows a range of VLANs to be forwarded on a given interface while maintaining data-plane segmentation between the VLANs.


Note


Trunk EFP (with or without port channel) supports encapsulation of up to 1000 VLANs.


Like a static EFP, this new type of EFP is user-configurable via the service instance trunk command, the encapsulation command, and the bridge-domain from-encapsulation command when the Trunk EFP Support feature is enabled.

Ethernet Flow Points

An Ethernet flow point (EFP) is a forwarding decision point in the provider edge (PE) router, which gives network designers flexibility to make many Layer 2 flow decisions within the interface. Many EFPs can be configured on a single physical port. (The number varies from one device to another.) EFPs are the logical demarcation points of an Ethernet virtual connection (EVC) on an interface. An EVC that uses two or more user network interfaces (UNIs) requires an EFP on the associated ingress and egress interfaces of every device that the EVC passes through.

EFPs can be configured on any Layer 2 traffic port; however, they are usually configured on UNI ports. The following parameters (matching criteria) can be configured on the EFP:

  • Frames of a specific VLAN, a VLAN range, or a list of VLANs (100-150 or 100,103,110)
  • Frames with no tags (untagged)
  • Frames with identical double-tags (VLAN tags) as specified
  • Frames with identical Class of Service (CoS) values

A frame passes each configured match criterion until the correct matching point is found. If a frame does not fit any of the matching criteria, it is dropped. Default criteria can be configured to avoid dropping frames.

The following types of commands can be used in an EFP:

  • Rewrite commands—In each EFP, VLAN tag management can be specified with the following actions:
    • Pop—1) pops out a tag; 2) pops out two tags
    • Push—1) pushes in a tag; 2) pushes in two tags
    • Translate—1 to 1) changes a tag value; 1 to 2) pops one tag and pushes two tags; 2 to 1) pops two tags and pushes one tag; 2 to 2) changes the value for two tags
  • Forwarding commands—Each EFP specifies the forwarding command for the frames that enter the EFP. Only one forwarding command can be configured per EFP. The forwarding options are as follows:
    • Layer 2 point-to-point forwarding to a pseudowire tunnel
    • Multipoint bridge forwarding to a bridge domain entity
    • Local switch-to-switch forwarding between two different interfaces
  • Feature commands—In each EFP, the QoS features or parameters can be changed and the ACL can be updated.

Trunk Ports

An Ethernet interface can be configured as a trunk port (interface). A trunk port, also known as a trunk, is a point-to-point link between a networking device and another networking device. Trunks carry the traffic of multiple VLANs over a single link and allow you to extend VLANs across an entire network. A trunk port configured on the interface with two or more VLANs can carry traffic for several VLANs simultaneously.

To correctly deliver the traffic on a trunk port with several VLANs, the device uses the IEEE 802.1Q encapsulation or tagging method.

How to Enable Trunk EFP Support

Enabling Trunk EFP Support

To enable Ethernet flow point (EFP) support on a trunk port or trunk interface, complete the following steps.

SUMMARY STEPS

    1.    enable

    2.    configure terminal

    3.    interface type number

    4.    service instance trunk id ethernet

    5.    encapsulation dot1q vlan-id [, vlan-id [- vlan-d]]

    6.    rewrite ingress tag pop 1 symmetric

    7.    bridge-domain from-encapsulation

    8.    no shutdown

    9.    end


DETAILED STEPS
 Command or ActionPurpose
Step 1 enable


Example:
Device> enable
 

Enables privileged EXEC mode.

  • Enter your password if prompted.
 
Step 2 configure terminal


Example:
Device# configure terminal
 

Enters global configuration mode.

 
Step 3 interface type number


Example:
Device(config)# interface gigabitethernet2/0/1
 

Configures the interface and enters interface configuration mode.

 
Step 4 service instance trunk id ethernet


Example:
Device(config-if)# service instance trunk 1 ethernet
 

Configures an Ethernet service instance on an interface and enters Ethernet service configuration mode.

 
Step 5 encapsulation dot1q vlan-id [, vlan-id [- vlan-d]]


Example:
Device(config-if-srv)# encapsulation dot1q 1-5, 7, 9-12
 

Defines the matching criteria to map 802.1Q frames ingress on an interface to the appropriate service instance.

 
Step 6 rewrite ingress tag pop 1 symmetric


Example:
Device(config-if-srv)# rewrite ingress tag pop 1 symmetric
 

Specifies the encapsulation adjustment to be performed on a frame that is entering a service instance.

 
Step 7 bridge-domain from-encapsulation


Example:
Device(config-if-srv)# bridge-domain from-encapsulation
 

Creates a list of bridge domains for an EFP trunk port using the bridge-domain IDs derived from the encapsulation VLAN numbers.

 
Step 8 no shutdown


Example:
Device(config-if-srv)# no shutdown
 

Disables shutdown and keeps the interface or port active.

 
Step 9 end


Example:
Device(config-if-srv)# end
 

Returns to privileged EXEC mode.

 

Verifying the Trunk EFP Support Configuration

Use one or more of the commands listed below to verify the Trunk EFP Support feature configuration.

SUMMARY STEPS

    1.    enable

    2.    show ethernet service instance

    3.    show ethernet service instance interface [interface]

    4.    show bridge-domain

    5.    exit


DETAILED STEPS
Step 1   enable


Example:
Device> enable

Enables privileged EXEC mode.

  • Enter your password if prompted.
Step 2   show ethernet service instance


Example:
Device# show ethernet service instance

Displays information about Ethernet service instances.

Step 3   show ethernet service instance interface [interface]


Example:
Device# show ethernet service instance interface gigabitethernet2/0/1

Displays interface-only information about Ethernet service instances for all interfaces or for a specified interface.

Step 4   show bridge-domain


Example:
Device# show bridge-domain

Displays bridge-domain information.

Step 5   exit


Example:
Device# exit

Exits privileged EXEC mode.


Configuration Examples for Trunk EFP Support

Example: Configuring Trunk EFP Support

In the following example, EFP support has been configured on a trunk interface.

Device> enable
Device# configure terminal
Device(config)# interface gigabitethernet2/0/1
Device(config-if)# service instance trunk 1 ethernet
Device(config-if-srv)# encapsulation dot1q 1 - 5, 7, 9 - 12  
Device(config-if-srv)# rewrite ingress tag pop 1 symmetric  
Device(config-if-srv)# bridge-domain from-encapsulation 
Device(config-if-srv)# no shutdown
Device(config-if-srv)# end

Example: Verifying the Trunk EFP Support Configuration

The following is sample output from the show ethernet service instance command. The output displays trunk as the service instance type and indicates that a bridge domain for VLANs in the range of 12 to 1900 (as specified by the encapsulation parameters) has been created for service instance 4000 on a trunk port (interface).

Device# show ethernet service instance id 4000 interface gigabitethernet0/0/5 detail 

Service Instance ID: 4000
Service Instance Type: Trunk
Associated Interface: GigabitEthernet0/0/5
Associated EVC: 
L2protocol drop
CE-Vlans:                                                                        
Encapsulation: dot1q 12-1900 vlan protocol type 0x8100
Rewrite: ingress tag pop 1 symmetric
Interface Dot1q Tunnel Ethertype: 0x8100
State: Up
EFP Statistics:
   Pkts In   Bytes In   Pkts Out  Bytes Out
168729725 10798985220  160246675 10255787200
EFP Microblocks:
****************
Microblock type: Bridge-domain
Bridge-domain: 12-1900