- 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
Contents
- Displaying and Clearing IP Access List Data Using ACL Manageability
- Finding Feature Information
- Information About Displaying and Clearing IP Access List Data Using ACL Manageability
- Benefits of ACL Manageability
- Support for Interface-Level ACL Statistics
- How to Display and Clear IP Access List Data
- Displaying Global IP ACL Statistics
- Displaying Interface-Level IP ACL Statistics
- Clearing the Access List Counters
- Configuration Examples for Displaying and Clearing IP Access List Data Using ACL Manageability
- Example Displaying Global IP ACL Statistics
- Example Displaying Input Statistics
- Example Displaying Output Statistics
- Example Displaying Input and Output Statistics
- Example Clearing Global and Interface Statistics for an IP Access List
- Example Clearing Global and Interface Statistics for All IP Access Lists
- Additional References
- Feature Information for Displaying IP Access List Information and Clearing Counters
Displaying and Clearing IP Access List Data Using ACL Manageability
This module describes how to display the entries in an IP access list and the number of packets that have matched each entry. Users can get these statistics globally, or per interface and per incoming or outgoing traffic direction, by using the ACL Manageability feature. Viewing details of incoming and outgoing traffic patterns on various interfaces of a network device can help secure devices against attacks coming in on a particular interface. This module also describes how to clear counters so that the count of packets matching an access list entry will restart from zero.
- Finding Feature Information
- Information About Displaying and Clearing IP Access List Data Using ACL Manageability
- How to Display and Clear IP Access List Data
- Configuration Examples for Displaying and Clearing IP Access List Data Using ACL Manageability
- Additional References
- Feature Information for Displaying IP Access List Information and Clearing Counters
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 Displaying and Clearing IP Access List Data Using ACL Manageability
Benefits of ACL Manageability
Prior to Cisco IOS Release 12.4(6)T, the ACL infrastructure in Cisco IOS software maintained only global statistics for each ACE in an ACL. With this method, if an ACL is applied to multiple interfaces, the maintained ACE statistics are the sum of incoming and outgoing packet matches (hits) on all the interfaces on which that ACL is applied.
However, if ACE statistics are maintained per interface and per incoming or outgoing traffic direction, users can view specific details of incoming and outgoing traffic patterns and the effectiveness of ACEs on the various interfaces of a network device. This type of information is useful for securing devices against attacks coming in on a particular interface.
Support for Interface-Level ACL Statistics
With Cisco IOS Release 12.4(6)T, the ACL infrastructure in Cisco IOS software is now extended to support the maintenance, display, and clearing of ACE statistics per interface and per incoming or outgoing traffic direction for ACLs. This support is often referred to as “support for interface-level statistics.”
Note | If the same access-group ACL is also used by other features, the maintained interface statistics are not updated when a packet match is detected by the other features. In this case, the sum of all the interface level statistics that are maintained for an ACL may not add up to the global statistics for that ACL. |
How to Display and Clear IP Access List Data
This section contains the following procedures for displaying IP access lists and the counts of packets that match (hit) each list, and for clearing IP access list counters.
Note | Alternatively, if you want to deny access to a particular host or network and find out if someone from that network or host is attempting to gain access, include the log keyword with the corresponding deny statement so that the packets denied from that source are logged for you. For more information, see the “IP Access List Logging” section of the “IP Access List Overview.” |
- Displaying Global IP ACL Statistics
- Displaying Interface-Level IP ACL Statistics
- Clearing the Access List Counters
Displaying Global IP ACL Statistics
Perform this task to display all IP access lists on the router and counts of packets that have matched.
1.
enable
2.
show
ip
access-list
[access-list-number | access-list-name]
DETAILED STEPS
Displaying Interface-Level IP ACL Statistics
This section describes how to display IP ACE statistics per interface and per incoming or outgoing traffic direction for ACLs. This feature is known as ACL Manageability.
1.
enable
2.
show
ip
access-list
interface
interface-name
[in| out]
DETAILED STEPS
Clearing the Access List Counters
The system counts how many packets match (hit) each line of an access list; the counters are displayed by the show access-lists EXEC command. Perform this task to clear the counters of an access list. You might do this if you are trying to determine a more recent count of packets that match an access list, starting from zero.
1.
enable
2.
clear
ip
access-list
counters
{access-list-number | access-list-name}
DETAILED STEPS
Command or Action | Purpose |
---|
Configuration Examples for Displaying and Clearing IP Access List Data Using ACL Manageability
- Example Displaying Global IP ACL Statistics
- Example Displaying Input Statistics
- Example Displaying Output Statistics
- Example Displaying Input and Output Statistics
- Example Clearing Global and Interface Statistics for an IP Access List
- Example Clearing Global and Interface Statistics for All IP Access Lists
Example Displaying Global IP ACL Statistics
The following example displays global statistics for ACL 150:
Router# show ip access-list 150 Extended IP access list 150 10 permit ip host 10.1.1.1 any (3 matches) 30 permit ip host 10.2.2.2 any (27 matches)
Example Displaying Input Statistics
The following example displays statistics on incoming packets gathered from the FastEthernet interface 0/1, associated with access list 150 (ACL number):
Router# show ip access-list interface FastEthernet 0/1 in Extended IP access list 150 in 10 permit ip host 10.1.1.1 any (3 matches) 30 permit ip host 10.2.2.2 any (12 matches)
Example Displaying Output Statistics
The following example displays statistics on outgoing packets gathered from the FastEthernet interface 0/0:
Router# show ip access-list interface FastEthernet 0/0 out Extended IP access list myacl out 5 deny ip any 10.1.0.0 0.0.255.255 10 permit udp any any eq snmp (6 matches)
Example Displaying Input and Output Statistics
Note | If no direction is specified, any input and output ACLs applied to that interface are displayed. |
The following example displays input and output statistics gathered from the FastEthernet interface 0/0:
Router# show ip access-list interface FastEthernet 0/0 Extended IP access list 150 in 10 permit ip host 10.1.1.1 any 30 permit ip host 10.2.2.2 any (15 matches) Extended IP access list myacl out 5 deny ip any 10.1.0.0 0.0.255.255 10 permit udp any any eq snmp (6 matches)
Example Clearing Global and Interface Statistics for an IP Access List
The following example clears global and interface statistics for IP ACL 150:
Router# clear ip access-list counters 150
Example Clearing Global and Interface Statistics for All IP Access Lists
The following example clears global and interface statistics for all IP ACLs:
Router# clear ip access-list counters
Additional References
Related Documents
Related Topic |
Document Title |
---|---|
Cisco IOS commands |
|
Security commands |
Cisco IOS Security Command Reference |
Standards
Standard |
Title |
---|---|
No new or modified standards are supported by this feature. |
-- |
MIBs
MIB |
MIBs Link |
---|---|
No new or modified MIBs are supported by this feature. |
To locate and download MIBs for selected platforms, Cisco IOS releases, and feature sets, use Cisco MIB Locator found at the following URL: |
RFCs
RFC |
Title |
---|---|
No new or modified standards are supported by this feature, and support for existing standards has not been modified by this feature. |
-- |
Technical Assistance
Description |
Link |
---|---|
The Cisco Support and Documentation website provides online resources to download documentation, software, and tools. Use these resources to install and configure the software and to troubleshoot and resolve technical issues with Cisco products and technologies. Access to most tools on the Cisco Support and Documentation website requires a Cisco.com user ID and password. |
Feature Information for Displaying IP Access List Information and Clearing Counters
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 |
---|---|---|
ACL Manageability |
Cisco IOS XE Release 3.9S |
The ACL Manageability feature enables users to display and clear Access Control Entry (ACE) statistics per interface and per incoming or outgoing traffic direction for access control lists (ACLs). |