Evcs - Cisco NCS 4200 Series Configuration Manual

EVCs

• L2 ACL is supported over port channel with Normal EFPs.
• Egress L2 ACL on EVC is not supported.
• L2 ACLs are not supported on Trunk EFP.
• L2 ACL counters are not supported.
• Layer2 ACL can be applied on layer 2 frame without IPv4 or IPv6 header as layer 2 ACL does not
• Layer 2 ACLs function inbound only. The Layer 2 ACLs are not supported at physical interface level.
EVCs
An Ethernet virtual circuit (EVC) as defined by the Metro Ethernet Forum is a port-level point-to-point or
multipoint-to-multipoint Layer 2 circuit. It is an end-to-end representation of a single instance of a Layer 2
service being offered by a provider to a customer. An EVC contains the different parameters on which the
service is being offered. A service instance is the instantiation of an EVC on a specified port.
Service instances are configured under a port channel. The traffic carried by the service instance is load
balanced across member links. Service instances under a port channel are grouped and each group is associated
with one member link. Ingress traffic for a single EVC can arrive on any member of the bundle. All egress
traffic for a service instance uses only one of the member links. Load balancing is achieved by grouping
service instances and assigning them to a member link.
Ethernet virtual connection services (EVCS) uses the EVCs and service instances to provide Layer 2 switched
Ethernet services. EVC status can be used by a customer edge (CE) device either to find an alternative path
to the service provider network or in some cases, to fall back to a backup path over Ethernet or over another
alternative service such as ATM.
For information about the Metro Ethernet Forum standards, see the Standards table in the "Additional
References" section.
Relationship Between ACLs and Ethernet Infrastructure
The following points capture the relationship between ACLs and Ethernet Infrastructure (EI):
• ACLs can be directly applied on an EVC using the command-line interface (CLI). An ACL is applied
• One ACL can be applied to more than one service instance at any time.
• One service instance can have one ACL at most applied to it at any time. If a Layer 2 ACL is applied
• Only named ACLs can be applied to service instances. The command syntax ACLs is retained; the mac
• The show ethernet service instance id id interface type number detail command can be used to
Layer 2 Configuration Guide for Cisco NCS 4200 Series
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support filter on IPv4 or IPv6 traffic.
to a service instance, which is the instantiation of an EVC on a given port.
to a service instance that already has a Layer 2 ACL, the new one replaces the old one.
access-list extended command is used to create an ACL.
provide details about ACLs on service instances.
Layer 2 Access Control Lists on EVCs