Table Of Contents
Layer 2 Access Control Lists on EVCs
Finding Feature Information
Contents
Prerequisites for Layer 2 Access Control Lists on EVCs
Restrictions for Layer 2 Access Control Lists on EVCs
Information About Layer 2 Access Control Lists on EVCs
EVC
Relationship Between ACLs and Ethernet Infrastructure
How to Configure Layer 2 Access Control Lists on EVCs
Creating a Layer 2 ACL
Applying a Layer 2 ACL to a Service Instance
Configuring a Layer 2 ACL with ACEs on a Service Instance
Verifying the Presence of a Layer 2 ACL on a Service Instance
Configuration Examples for Layer 2 Access Control Lists on EVCs
Creating a Layer 2 ACL with ACEs: Example
Applying a Layer 2 ACL to a Service Instance: Example
Applying a Layer 2 ACL to Three Service Instances on the Same Interface: Example
Displaying the Details of a Layer 2 ACL on a Service Instance: Example
Additional References
Related Documents
Standards
MIBs
RFCs
Technical Assistance
Command Reference
Feature Information for Layer 2 Access Control Lists on EVCs
Layer 2 Access Control Lists on EVCs
First Published: October 24, 2008
Last Updated: October 24, 2008
The ability to filter packets in a modular and scalable way is important for both network security and network management. Access Control Lists (ACLs) provide the capability to filter packets at a fine granularity. In Metro Ethernet networks, ACLs are directly applied on Ethernet virtual circuits (EVCs).
Layer 2 Access Control Lists on EVCs is a security feature that allows packet filtering based on MAC addresses. This module describes how to implement ACLs on EVCs.
Finding Feature Information
Your software release may not support all the features documented in this module. For the latest feature information and caveats, see the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the "Feature Information for Layer 2 Access Control Lists on EVCs" section.
Use Cisco Feature Navigator to find information about platform support and Cisco IOS, Catalyst OS, and Cisco IOS XE software image support. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.
Contents
•
Prerequisites for Layer 2 Access Control Lists on EVCs
•
Restrictions for Layer 2 Access Control Lists on EVCs
•
Information About Layer 2 Access Control Lists on EVCs
•
How to Configure Layer 2 Access Control Lists on EVCs
•
Configuration Examples for Layer 2 Access Control Lists on EVCs
•
Additional References
•
Command Reference
•
Feature Information for Layer 2 Access Control Lists on EVCs
Prerequisites for Layer 2 Access Control Lists on EVCs
•
Knowledge of how service instances must be configured.
•
Knowledge of extended MAC ACLs and how they must be configured.
Restrictions for Layer 2 Access Control Lists on EVCs
•
A maximum of 16 access control entries (ACEs) are allowed for a given ACL.
•
Only 256 different or unique Layer 2 ACLs can be configured on a line card. (More than 256 ACLs can be configured on a router.)
•
Layer 2 ACLs function inbound only.
•
Current Layer 2 ACLs provide Layer 3 filtering options in permit and deny rules. Options that are not relevant to service instances are ignored.
Information About Layer 2 Access Control Lists on EVCs
To implement Layer 2 ACLs on EVCs, you should understand the following concepts:
•
EVC
•
Relationship Between ACLs and Ethernet Infrastructure
EVC
An 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. It embodies the different parameters on which the service is being offered. A service instance is the instantiation of an EVC on a given port on a given router.
Ethernet virtual connection services (EVCS) uses EVCs and service instances to provide Layer 2 switched Ethernet services. The EVC status can be used by a customer edge (CE) device either to find an alternative path in to the service provider network or, in some cases, to revert to a backup path over Ethernet or over another alternative service such as Frame Relay or ATM.
For information about the Metro Ethernet Forum standards, see the "Standards" 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 to a service instance, which is the instantiation of an EVC on a given port.
•
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 to a service instance that already has a Layer 2 ACL, the new one replaces the old one.
•
Only named ACLs can be applied to service instances. The command syntax ACLs is retained; the mac access-list extended command is used to create an ACL.
•
The show ethernet service instance command can be used to provide details about ACLs on service instances.
How to Configure Layer 2 Access Control Lists on EVCs
This section contains the following procedures:
•
Creating a Layer 2 ACL
•
Applying a Layer 2 ACL to a Service Instance
•
Configuring a Layer 2 ACL with ACEs on a Service Instance
•
Verifying the Presence of a Layer 2 ACL on a Service Instance
Creating a Layer 2 ACL
Perform this task to create a Layer 2 ACL with a single ACE.
SUMMARY STEPS
1.
enable
2.
configure terminal
3.
mac access-list extended name
4.
permit {{src-mac mask | any} {dest-mac mask | any} [protocol [vlan vlan] [cos value]]}
DETAILED STEPS
| |
Command or Action
|
Purpose
|
Step 1
|
enable
Example:
Router> enable
|
Enables privileged EXEC mode.
• Enter your password if prompted.
|
Step 2
|
configure terminal
Example:
Router# configure terminal
|
Enters global configuration mode.
|
Step 3
|
mac access-list extended name
Example:
Router(config)# mac access-list extended
test-12-acl
|
Defines an extended MAC ACL and places the CLI in mac access list control configuration mode.
|
Step 4
|
permit {{src-mac mask | any} {dest-mac mask |
any} [protocol [vlan vlan] [cos value]]}
Example:
Router(config-ext-macl)# permit 00aa.00bb.00cc
0.0.0 any
|
Allows forwarding of Layer 2 traffic if the conditions are matched. Creates an ACE for the ACL.
|
Applying a Layer 2 ACL to a Service Instance
Perform this task to apply a Layer 2 ACL to a service instance.
Note
Note that packet filtering takes place only after the ACL has been created and applied to the service instance.
Prerequisites
Before applying an ACL to a service instance, you must create it using the mac access-list extended command. See the "Creating a Layer 2 ACL" section.
SUMMARY STEPS
1.
enable
2.
configure terminal
3.
interface type number
4.
service instance id ethernet
5.
encapsulation dot1q vlan-id
6.
mac access-group access-list-name in
DETAILED STEPS
| |
Command or Action
|
Purpose
|
Step 1
|
enable
Example:
Router> enable
|
Enables privileged EXEC mode.
• Enter your password if prompted.
|
Step 2
|
configure terminal
Example:
Router# configure terminal
|
Enters global configuration mode.
|
Step 3
|
interface type number
Example:
Router(config)# interface gigabitethernet 1/0/0
|
Specifies the type and location of the interface to configure, where:
• type—Specifies the type of the interface.
• number—Specifies the location of the interface.
|
Step 4
|
service instance id ethernet
Example:
Router(config-if)# service instance 100
ethernet
|
Configures an Ethernet service instance on an interface and places the CLI in Ethernet service configuration mode.
|
Step 5
|
encapsulation dot1q vlan-id
Example:
Router(config-if-srv)# encapsulation dot1q 100
|
Defines the matching criteria to be used in order to map ingress dot1q frames on an interface to the appropriate service instance.
|
Step 6
|
mac access-group access-list-name in
Example:
Router(config-if-srv)# mac access-group
test-12-acl in
|
Applies a MAC ACL to control incoming traffic on the interface.
|
Configuring a Layer 2 ACL with ACEs on a Service Instance
Perform this task to configure the same ACL with three ACEs and stop all other traffic on a service instance.
SUMMARY STEPS
1.
enable
2.
configure terminal
3.
mac access-list extended name
4.
permit {src-mac mask | any} {dest-mac mask | any}
5.
permit {src-mac mask | any} {dest-mac mask | any}
6.
permit {src-mac mask | any} {dest-mac mask | any}
7.
deny any any
8.
exit
9.
interface type number
10.
service instance id ethernet
11.
encapsulation dot1q vlan-id
12.
mac access-group access-list-name in
| |
Command or Action
|
Purpose
|
Step 1
|
enable
Example:
Router> enable
|
Enables privileged EXEC mode.
• Enter your password if prompted.
|
Step 2
|
configure terminal
Example:
Router# configure terminal
|
Enters global configuration mode.
|
Step 3
|
mac access-list extended name
Example:
Router(config)# mac access list extended
test-12-acl
|
Defines an extended MAC ACL and enters mac access control list configuration mode.
|
Step 4
|
permit {src-mac mask | any} {dest-mac mask |
any}
Example:
Router(config-ext-macl)# permit 00aa.bbcc.ddea
0.0.0 any
|
Allows forwarding of Layer 2 traffic if the conditions are matched. This creates an ACE for the ACL.
|
Step 5
|
permit {src-mac mask | any} {dest-mac mask |
any}
Example:
Router(config-ext-macl)# permit 00aa.bbcc.ddeb
0.0.0 any
|
Allows forwarding of Layer 2 traffic if the conditions are matched. This creates an ACE for the ACL.
|
Step 6
|
permit {src-mac mask | any} {dest-mac mask} |
any}
Example:
Router(config-ext-macl)# permit 00aa.bbcc.ddec
0.0.0 any
|
Allows forwarding of Layer 2 traffic if the conditions are matched. This creates an ACE for the ACL.
|
Step 7
|
deny any any
Example:
Router(config-ext-macl)# deny any any
|
Prevents forwarding of Layer 2 traffic except for the allowed ACEs.
|
Step 8
|
exit
Example:
Router(config-ext-macl)# exit
|
Exits the current command mode and returns the CLI to global configuration mode.
|
Step 9
|
interface type number
Example:
Router(config)# interface gigabitethernet 1/0/0
|
Specifies the interface.
|
Step 10
|
service instance id ethernet
Example:
Router(config-if)# service instance 200
ethernet
|
Configures an Ethernet service instance on an interface and places the CLI in service instance configuration mode.
|
Step 11
|
encapsulation dot1q vlan-id
Example:
Router(config-if-srv)# encapsulation dot1q 100
|
Defines the matching criteria to be used to map ingress dot1q frames on an interface to the appropriate service instance.
|
Step 12
|
mac access-group access-list-name in
Example:
Router(config-if-srv)# mac access-group
test-12-acl in
|
Applies a MAC ACL to control incoming traffic on the interface.
|
DETAILED STEPS
Verifying the Presence of a Layer 2 ACL on a Service Instance
Perform this task to verify that a Layer 2 ACL is present on an EVC. This verification task can be used after an ACL has been configured to confirm its presence.
SUMMARY STEPS
1.
enable
2.
configure terminal
3.
show ethernet service instance id id interface type number detail
DETAILED STEPS
| |
Command or Action
|
Purpose
|
Step 1
|
enable
Example:
Router> enable
|
Enables privileged EXEC mode.
• Enter your password if prompted.
|
Step 2
|
configure terminal
Example:
Router# show ethernet service instance id 100
interface gigabitethernet 3/0/1 detail
|
Enters global configuration mode.
|
Step 3
|
show ethernet service instance id id interface
type number detail
Example:
Router# show ethernet service instance id 100
interface gigabitethernet 3/0/1 detail
|
Displays detailed information about Ethernet customer service instances.
|
Configuration Examples for Layer 2 Access Control Lists on EVCs
This section provides the following configuration examples:
•
Creating a Layer 2 ACL with ACEs: Example
•
Applying a Layer 2 ACL to a Service Instance: Example
•
Applying a Layer 2 ACL to Three Service Instances on the Same Interface: Example
•
Displaying the Details of a Layer 2 ACL on a Service Instance: Example
Creating a Layer 2 ACL with ACEs: Example
The following example shows how to create a Layer 2 ACL called mac-11-acl with two permitted ACEs:
mac access-list extended mac-11-acl
permit 00aa.00bb.00cc 1a11.0101.11c1 any
permit 00aa.00bb.00cc 1a11.0101.11c2 any
Applying a Layer 2 ACL to a Service Instance: Example
The following example shows how to apply a Layer 2 ACL called mac-20-acl to a service instance. The ACL has five permitted ACEs and all other traffic is not allowed.
mac access-list extended mac-20-acl
permit 00aa.bbcc.adec 0.0.0 any
permit 00aa.bbcc.bdec 0.0.0 any
permit 00aa.bbcc.cdec 0.0.0 any
permit 00aa.bbcc.edec 0.0.0 any
permit 00aa.bbcc.fdec 0.0.0 any
interface gigabitethernet 10/0/0
service instance 100 ethernet
mac access-group mac-20-acl in
Applying a Layer 2 ACL to Three Service Instances on the Same Interface: Example
The following example shows how to apply a Layer 2 ACL called mac-07-acl to three service instances on the same interface:
mac access-list extended mac-07-acl
permit 00aa.bbcc.adec 0.0.0 any
permit 00aa.bbcc.bdec 0.0.0 any
permit 00aa.bbcc.cdec 0.0.0 any
interface gigabitethernet 10/0/0
service instance 100 ethernet
mac access-group mac-07-acl in
service instance 101 ethernet
mac access-group mac-07-acl in
service instance 102 ethernet
mac access-group mac-07-acl in
Displaying the Details of a Layer 2 ACL on a Service Instance: Example
The following sample output displays the details of a Layer 2 ACL called test-acl on a service instance.
Router# show ethernet service instance id 100 int e0/0 detail
L2 ACL (inbound): test-acl
Associated Interface: Ethernet0/0
Interface Dot1q Tunnel Ethertype: 0x8100
L2 ACL permit count: 10255
Table 1 describes the significant fields in the output.
Table 1 show ethernet service instance Field Descriptions
Field
|
Description
|
Service Instance ID
|
Displays the service instance ID.
|
L2 ACL (inbound):
|
Displays the ACL name.
|
Associated Interface:
|
Displays the interface details of the service instance.
|
Associated EVC:
|
Displays the EVC with which the service instance is associated.
|
CEVlans:
|
Displays details of the associated VLAN ID.
|
State:
|
Displays whether the service instance is in an up or down state.
|
L2 ACL permit count:
|
Displays the number of packet frames allowed to pass on the service instance by the ACL.
|
L2 ACL deny count
|
Displays the number of packet frames not permitted to pass on the service instance by the ACL.
|
Additional References
The following sections provide references related to the Layer 2 Access Control Lists on EVCs feature.
Related Documents
Standards
Standard
|
Title
|
MEF 6.1
|
Metro Ethernet Services Definitions Phase 2 (PDF 6/08)
|
MEF 10.1
|
Ethernet Services Attributes Phase 2 (PDF 10/06)
|
MIBs
MIB
|
MIBs Link
|
• None
|
To locate and download MIBs for selected platforms, Cisco IOS releases, and feature sets, use Cisco MIB Locator found at the following URL:
http://www.cisco.com/go/mibs
|
RFCs
RFC
|
Title
|
No new or modified RFCs are supported by this release.
|
—
|
Technical Assistance
Description
|
Link
|
The Cisco Support website provides extensive online resources, including documentation and tools for troubleshooting and resolving technical issues with Cisco products and technologies.
To receive security and technical information about your products, you can subscribe to various services, such as the Product Alert Tool (accessed from Field Notices), the Cisco Technical Services Newsletter, and Really Simple Syndication (RSS) Feeds.
Access to most tools on the Cisco Support website requires a Cisco.com user ID and password.
|
http://www.cisco.com/techsupport
|
Command Reference
The following commands are introduced or modified in the feature or features documented in this module. For information about these commands, see the Cisco IOS Carrier Ethernet Command Reference at http://www.cisco.com/en/US/docs/ios/carrier_ethernet/command/reference/ce_book.html. For information about all Cisco IOS commands, use the Command Lookup Tool at http://tools.cisco.com/Support/CLILookup or the Cisco IOS Master Command List, All Releases, at http://www.cisco.com/en/US/docs/ios/mcl/allreleasemcl/all_book.html.
•
interface
•
mac access-group in
•
mac access-list extended
•
show ethernet service instance
Feature Information for Layer 2 Access Control Lists on EVCs
Table 2 lists the release history for this feature.
Not all commands may be available in your Cisco IOS software release. For release information about a specific command, see the command reference documentation.
Use Cisco Feature Navigator to find information about platform support and software image support. Cisco Feature Navigator enables you to determine which Cisco IOS, Catalyst OS, and Cisco IOS XE software images support a specific software release, feature set, or platform. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.
Note
Table 2 lists only the Cisco IOS software release that introduced support for a given feature in a given Cisco IOS software release train. Unless noted otherwise, subsequent releases of that Cisco IOS software release train also support that feature.
Table 2 Feature Information for Layer 2 Access Control Lists on EVCs
Feature Name
|
Releases
|
Feature Information
|
Layer 2 Access Control Lists on EVCs
|
12.2(33)SRD
|
The Layer 2 Access Control Lists on EVCs feature introduces ACLs on EVCs.
The following commands were introduced or modified: interface, mac access-group in, mac access-list extended, show ethernet service instance.
|
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