- IP Access List Overview
- Creating an IP Access List and Applying It to an Interface
- Creating an IP Access List to Filter IP Options, TCP Flags, Noncontiguous Ports
- Configuring an FQDN ACL
- Refining an IP Access List
- IP Named Access Control Lists
- Commented IP Access List Entries
- Standard IP Access List Logging
- IP Access List Entry Sequence Numbering
- Configuring Lock-and-Key Security (Dynamic Access Lists)
- ACL IP Options Selective Drop
- Displaying and Clearing IP Access List Data Using ACL Manageability
- ACL Syslog Correlation
- IPv6 Access Control Lists
- IPv6 ACL Undetermined-Transport Support
- Configuring Template ACLs
- IPv6 Template ACL
- IPv4 ACL Chaining Support
- IPv6 ACL Chaining with a Common ACL
- IPv6 ACL Extensions for Hop by Hop Filtering
- Finding Feature Information
- Information About IPv6 ACL Chaining with a Common ACL
- How to Configure IPv6 ACL Chaining with a Common ACL
- Configuration Examples for IPv6 ACL Chaining with a Common ACL
- Additional References for IPv6 ACL Chaining with a Common ACL
- Feature Information for IPv6 ACL Chaining with a Common ACL
IPv6 ACL Chaining with a Common ACL
ACL Chaining, also known as Multi-Access Control List (ACL), allows you to split ACLs. This document describes how with the IPv6 ACL Chaining Support feature, you can explicitly split ACLs into common and user-specific ACLs and bind both ACLs to a target for traffic filtering on a device. In this way, the common ACLs in Ternary Content Addressable Memory (TCAM) are shared by multiple targets, thereby reducing the resource usage.
- Finding Feature Information
- Information About IPv6 ACL Chaining with a Common ACL
- How to Configure IPv6 ACL Chaining with a Common ACL
- Configuration Examples for IPv6 ACL Chaining with a Common ACL
- Additional References for IPv6 ACL Chaining with a Common ACL
- Feature Information for IPv6 ACL Chaining with a Common ACL
Finding Feature Information
Your software release may not support all the features documented in this module. For the latest caveats and feature information, see Bug Search Tool and 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 table at the end of this module.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.
Information About IPv6 ACL Chaining with a Common ACL
ACL Chaining Overview
The packet filter process supports only a single Access control list (ACL) to be applied per direction and per protocol on an interface. This leads to manageability and scalability issues if there are common ACL entries needed on many interfaces. Duplicate Access control entries (ACEs) are configured for all those interfaces, and any modification to the common ACEs needs to be performed for all ACLs.
The purpose of these address blocks is to deny access to ISP's protected infrastructure networks and anti-spoofing protection by allowing only customer source address blocks. This results in configuring unique ACL per interface and most of the ACEs being common across all ACLs on a device. ACL provisioning and modification is very cumbersome, hence, any changes to the ACE impacts every target.
IPv6 ACL Chaining with a Common ACL
With IPv6 ACL Chaining, you can configure a traffic filter with the following:
Each Access control list (ACL) is matched in a sequence. For example, if you have specified both the ACLs - a common and a specific ACL, the packet is first matched against the common ACL; if a match is not found, it is then matched against the specific ACL.
Note | Any IPv6 ACL may be configured on a traffic filter as a common or specific ACL. However, the same ACL cannot be specified on the same traffic filter as both common and specific. |
How to Configure IPv6 ACL Chaining with a Common ACL
Note | You may choose to configure either of the following: |
The ipv6 traffic-filter command is not additive. When you use the command, it replaces earlier instances of the command. For example, the command sequence: ipv6 traffic-filter [common common-acl] [specific-acl] in ipv6 traffic-filter [specific-acl] in binds a common ACL to the traffic filter, removes the common ACL and then binds a specific ACL.
Configuring the IPv6 ACL to an Interface
Perform this task to configure the interface to accept a common access control list (ACL) along with an interface-specific ACL:
1.
enable
2.
configure
terminal
3.
interface
type number}
4.
ipv6
traffic filter
{common-access-list-name {in | out}}
5.
end
DETAILED STEPS
Configuration Examples for IPv6 ACL Chaining with a Common ACL
You may configure the following combinations in no particular order:
Example: Configuring an Interface to Accept a Common ACL
This example shows how to replace an access control list (ACL) configured on the interface without explicitly deleting the ACL:
interface gigabitethernet 0/0/0 ipv6 access-group common C_acl ACL1 in end replace interface acl ACL1 by ACL2 interface gigabitethernet 0/0/0 ipv6 access-group common C_acl ACL2 in end
This example shows how to delete a common ACL from an interface. A common ACL cannot be replaced on interfaces without deleting it explicitly from the interface.
interface gigabitethernet 0/0/0 ipv6 access-group common C_acl1 ACL1 in end change the common acl to C_acl2 interface gigabitethernet 0/0/0 no ipv6 access-group common C_acl1 ACL1 in end interface gigabitethernet 0/0/0 ipv6 access-group common C_acl2 ACL1 in end
Note | When reconfiguring a common ACL, you must ensure that no other interface on the line card is attached to the common ACL. |
Note | If both common ACL and interface ACL are attached to an interface and only one of the above is reconfigured on the interface, then the other is removed automatically. |
This example shows how to remove the interface ACL:
interface gigabitethernet 0/0/0 ipv6 access-group common C_acl1 ACL1 in end
Additional References for IPv6 ACL Chaining with a Common ACL
Related Documents
Related Topic | Document Title |
---|---|
IPv4 ACL Chaining Support |
Security Configuration Guide: Access Control Lists, Cisco IOS XE Release 3S |
Cisco IOS commands |
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Security commands |
Technical Assistance
Description | Link |
---|---|
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Feature Information for IPv6 ACL Chaining with a Common ACL
The following table provides release information about the feature or features described in this module. This table lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.
Feature Name |
Releases |
Feature Information |
---|---|---|
IPv6 ACL Chaining with a Common ACL |
Cisco IOS XE Release 3.11S Cisco IOS XE Release 3.6E |
The ACL Chaining feature, also known as Multi-ACLs, allows you to explicitly split IPv6 traffic filter access control lists (ACLs) into common and per-session ACLs. In this way, the common access control entries (ACEs) that are used reduces resource usage of each ACL entry per session in the Ternary Content Addressable Memory (TCAM). The following commands were introduced or modified: ip access-group common. |