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This chapter describes how to configure MAC access lists (ACLs) on Cisco NX-OS devices.
This chapter contains the following sections:
Your software release might not support all the features documented in this module. For the latest caveats and feature information, see the Bug Search Tool at https://tools.cisco.com/bugsearch/ and the release notes for your 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 "New and Changed Information"chapter or the Feature History table in this chapter.
MAC ACLs are ACLs that use information in the Layer 2 header of packets to filter traffic. MAC ACLs share many fundamental concepts with IP ACLs, including support for virtualization.
MAC packet classification allows you to control whether a MAC ACL that is on a Layer 2 interface applies to all traffic entering the interface, including IP traffic, or to non-IP traffic only.
MAC packet classification does not work on the Layer 3 control plane protocols such as HSRP, VRRP, OSPF, and so on. If you enable MAC packet classification on the VLANs, the basic functionalities will break on these protocols.
| MAC Packet Classification State | Effect on Interface |
|---|---|
|
Enabled |
|
|
Disabled |
|
There are no prerequisites for configuring MAC ACLs.
MAC ACLs have the following configuration guidelines and limitations:
MAC ACLs apply to ingress traffic only.
ACL statistics are not supported if the DHCP snooping feature is enabled.
This table lists the default settings for MAC ACL parameters.
|
Parameters |
Default |
|---|---|
|
MAC ACLs |
No MAC ACLs exist by default |
|
ACL rules |
Implicit rules apply to all ACLs |
You can create a MAC ACL and add rules to it.
| Command or Action | Purpose | |
|---|---|---|
|
Step 1 |
configure terminal Example: |
Enters global configuration mode. |
|
Step 2 |
mac access-list name Example: |
Creates the MAC ACL and enters ACL configuration mode. |
|
Step 3 |
{permit | deny} source destination protocol Example: |
Creates a rule in the MAC ACL. The permit and deny commands support many ways of identifying traffic. For more information, see the Cisco Nexus 7000 Series NX-OS Security Command Reference. |
|
Step 4 |
(Optional) statistics per-entry Example: |
(Optional)
Specifies that the device maintains global statistics for packets that match the rules in the ACL. |
|
Step 5 |
(Optional) show mac access-lists name Example: |
(Optional)
Displays the MAC ACL configuration. |
|
Step 6 |
(Optional) copy running-config startup-config Example: |
(Optional)
Copies the running configuration to the startup configuration. |
You can remove a MAC ACL from the device.
Use the show mac access-lists command with the summary keyword to find the interfaces that a MAC ACL is configured on.
| Command or Action | Purpose | |
|---|---|---|
|
Step 1 |
configure terminal Example: |
Enters global configuration mode. |
|
Step 2 |
mac access-list name Example: |
Enters ACL configuration mode for the ACL that you specify by name. |
|
Step 3 |
(Optional) [sequence-number] {permit | deny} source destination protocol Example: |
(Optional)
Creates a rule in the MAC ACL. Using a sequence number allows you to specify a position for the rule in the ACL. Without a sequence number, the rule is added to the end of the rules. The permit and deny commands support many ways of identifying traffic. For more information, see the Cisco Nexus 7000 Series NX-OS Security Command Reference. |
|
Step 4 |
(Optional) no {sequence-number | {permit | deny} source destination protocol} Example: |
(Optional)
Removes the rule that you specify from the MAC ACL. The permit and deny commands support many ways of identifying traffic. For more information, see the Cisco Nexus 7000 Series NX-OS Security Command Reference. |
|
Step 5 |
(Optional) [no] statistics per-entry Example: |
(Optional)
Specifies that the device maintains global statistics for packets that match the rules in the ACL. The no option stops the device from maintaining global statistics for the ACL. |
|
Step 6 |
(Optional) show mac access-lists name Example: |
(Optional)
Displays the MAC ACL configuration. |
|
Step 7 |
(Optional) copy running-config startup-config Example: |
(Optional)
Copies the running configuration to the startup configuration. |
You can change all the sequence numbers assigned to rules in a MAC ACL. Resequencing is useful when you need to insert rules into an ACL and there are not enough available sequence numbers.
| Command or Action | Purpose | |
|---|---|---|
|
Step 1 |
configure terminal Example: |
Enters global configuration mode. |
|
Step 2 |
resequence mac access-list name starting-sequence-number increment Example: |
Assigns sequence numbers to the rules contained in the ACL, where the first rule receives the number specified by the starting-sequence number that you specify. Each subsequent rule receives a number larger than the preceding rule. The difference in numbers is determined by the increment number that you specify. |
|
Step 3 |
(Optional) show mac access-lists name Example: |
(Optional)
Displays the MAC ACL configuration. |
|
Step 4 |
(Optional) copy running-config startup-config Example: |
(Optional)
Copies the running configuration to the startup configuration. |
You can remove a MAC ACL from the device.
| Command or Action | Purpose | |
|---|---|---|
|
Step 1 |
configure terminal Example: |
Enters global configuration mode. |
|
Step 2 |
no mac access-list name Example: |
Removes the MAC ACL that you specify by name from the running configuration. |
|
Step 3 |
(Optional) show mac access-lists name summary Example: |
(Optional)
Displays the MAC ACL configuration. If the ACL remains applied to an interface, the command lists the interfaces. |
|
Step 4 |
(Optional) copy running-config startup-config Example: |
(Optional)
Copies the running configuration to the startup configuration. |
You can apply a MAC ACL as a port ACL to any of the following interface types:
Layer 2 or Layer 3 Ethernet interfaces
Layer 2 or Layer 3 port-channel interfaces
Ensure that the ACL that you want to apply exists and is configured to filter traffic in the manner that you need for this application.
| Command or Action | Purpose | |
|---|---|---|
|
Step 1 |
configure terminal Example: |
Enters global configuration mode. |
|
Step 2 |
Enter one of the following commands:
Example:Example: |
|
|
Step 3 |
mac port access-group access-list Example: |
Applies a MAC ACL to the interface. |
|
Step 4 |
(Optional) show running-config aclmgr Example: |
(Optional)
Displays ACL configuration. |
|
Step 5 |
(Optional) copy running-config startup-config Example: |
(Optional)
Copies the running configuration to the startup configuration. |
You can apply a MAC ACL as a VACL.
You can enable or disable MAC packet classification on a Layer 2 interface.
The interface must be configured as a Layer 2 interface. Note that the M1 and M2 Series modules do not support IP ACLs on port ACL and VACL policies, when the MAC packet classification feature is enabled on the interface. Before you upgrade to Cisco NX-OS Release 6.x or later versions, you need to disable the MAC packet classification feature on M1 and M2 Series modules, and verify whether all the existing functionalities work. This limitation is not applicable for M3 series modules.
 Note |
If the interface is configured with the ip port access-group command or the ipv6 port traffic-filter command, you cannot enable MAC packet classification until you remove the ip port access-group and ipv6 port traffic-filter commands from the interface configuration. |
| Command or Action | Purpose | |
|---|---|---|
|
Step 1 |
configure terminal Example: |
Enters global configuration mode. |
|
Step 2 |
Enter one of the following commands:
Example:Example: |
|
|
Step 3 |
[no] mac packet-classify Example: |
Enables MAC packet classification on the interface. The no option disables MAC packet classification on the interface. |
|
Step 4 |
(Optional) Enter one of the following commands:
Example:Example: |
(Optional)
|
|
Step 5 |
(Optional) copy running-config startup-config Example: |
(Optional)
Copies the running configuration to the startup configuration. |
To display MAC ACL configuration information, perform one of the following tasks. For detailed information about the fields in the output from these commands, see the Cisco Nexus 7000 Series NX-OS Security Command Reference.
|
Command |
Purpose |
|---|---|
|
show mac access-lists |
Displays the MAC ACL configuration. |
|
show running-config aclmgr [all] |
Displays the ACL configuration, including MAC ACLs and the interfaces to which MAC ACLs are applied. |
|
show startup-config aclmgr [all] |
Displays the ACL startup configuration. |
Use the show mac access-lists command to monitor statistics about a MAC ACL, including the number of packets that have matched each rule.
To monitor or clear MAC ACL statistics, use one of the commands in this table. For detailed information about these commands, see the Cisco Nexus 7000 Series NX-OS Security Command Reference.
|
Command |
Purpose |
|---|---|
|
show mac access-lists |
Displays the MAC ACL configuration. If the MAC ACL includes the statistics per-entry command, the show mac access-lists command output includes the number of packets that have matched each rule. |
|
clear mac access-list counters |
Clears statistics for all MAC ACLs or for a specific MAC ACL. |
The following example shows how to create a MAC ACL named acl-mac-01 and apply it to Ethernet interface 2/1, which is a Layer 2 interface in this example:
mac access-list acl-mac-01
permit 00c0.4f00.0000 0000.00ff.ffff any
interface ethernet 2/1
mac port access-group acl-mac-01
|
Related Topic |
Document Title |
|---|---|
|
MAC ACL commands: complete command syntax, command modes, command history, defaults, usage guidelines, and examples |
Cisco Nexus 7000 Series NX-OS Security Command Reference |
|
Standards |
Title |
|---|---|
|
No new or modified standards are supported by this feature, and support for existing standards has not been modified by this feature. |
— |
This table lists the release history for this feature.
|
Feature Name |
Releases |
Feature Information |
|---|---|---|
|
MAC ACLs |
6.1(1) |
Updated for M2 Series modules. |
|
MAC ACLs |
6.0(1) |
Updated for F2 Series modules. |
|
MAC ACLs |
5.2(1) |
Changed the show running-config aclmgr and show startup-config aclmgr commands to display only the user-configured ACLs (and not also the default CoPP-configured ACLs) in the running and startup configurations. |
|
MAC ACLs |
5.0(2) |
Support was added for up to 128,000 ACL entries when using an XL line card, provided a scalable services license is installed. |
|
MAC ACLs |
4.2(1) |
Support was added for MAC packet classification. |
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