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Cisco ASR 901 Series Aggregation Services Router Software Configuration Guide
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Chapter 8 Configuring Ethernet Virtual Connections
Understanding EVC Features
Use the service instance number ethernet [name] interface configuration command to create an EFP on
a Layer 2 interface or EtherChannel and to enter service instance configuration mode. You use service
instance configuration mode to configure all management and control date plane attributes and
parameters that apply to the service instance on a per-interface basis.
• The service instance number is the EFP identifier, an integer from 1 to 8000.
• The optional ethernet name is the name of a previously configured EVC. You do not need to enter
an EVC name, but you must enter ethernet. Different EFPs can share the same name when they
correspond to the same EVC. EFPs are tied to a global EVC through the common name.
When you enter service instance configuration mode, you can configure these options:
• default—Sets a command to its defaults
• description—Adds a service instance specific description
• encapsulation—Configures Ethernet frame match criteria
• ethernet—Configures Ethernet-lmi parameters
• exit— Exits from service instance configuration mode
• no—Negates a command or sets its defaults
• service-policy —Attaches a policy-map to an EFP
• shutdown—Takes the service instance out of service
Enter the [no] shutdown service-instance configuration mode to shut down or bring up a service
instance.
On a Layer 2 port with no service instance configured, multiple switchport commands are available
(access, backup, block, host, mode, and trunk). When one or more service instances are configured on
a Layer 2 port, no switchport commands are accepted on that interface.
Encapsulation
Encapsulation defines the matching criteria that maps a VLAN, a range of VLANs, Ethertype, or a
combination of these to a service instance. Configure encapsulation in the service instance configuration
mode. You must configure one encapsulation command per EFP (service instance).
Use the encapsulation command in service-instance configuration mode to set the encapsulation
criteria. Different types of encapsulations are dot1q, dot1ad, and untagged. Valid Ethertypes (type) are
IPv4, PPPOE-All, PPPOE-Discover, and PPPOE-Session.
Encapsulation classification options also include:
• outer tag VLAN
• inner tag VLAN
• payload ethertype—any ethertype tag after the VLAN tag
After you enter an encapsulation method, these keyword options are available in service instance
configuration mode:
• bridge-domain—Configures a bridge domain
• rewrite—Configures Ethernet rewrite criteria
