C Commands

This chapter describes the Cisco NX-OS security commands that begin with C.

checkpoint

To take a snapshot of the current running configuration and store the snapshot in the file system in an ASCII format, use the checkpoint command.

checkpoint [ checkpoint-name [ description descp-text [... description descp-text ]] | description descp-text | file { bootflash: | volatile: }[ // server ][ directory / ][ filename ]]

no checkpoint [ checkpoint-name | description descp-text | file { bootflash: | volatile: }[ // server ][ directory / ][ filename ]]

 
Syntax Description

checkpoint-name

(Optional) Checkpoint name. The name can be a maximum of 32 characters.

description descp-text

(Optional) Specifies a description for the given checkpoint. The text can be a maximum of 80 characters and can contain spaces.

file

(Optional) Specifies that a file be created to store the configuration rollback checkpoint.

bootflash:

Specifies the bootflash local writable storage file system.

volatile:

Specifies the volatile local writable storage file system.

// server

(Optional) Name of the server. Valid values are ///, //module-1/, //sup-1/, //sup-active/, or //sup-local/. The double slash (//) is required.

directory /

(Optional) Name of a directory. The directory name is case sensitive.

filename

(Optional) Name of the checkpoint configuration file. The filename is case sensitive.


Note There can be no spaces in the filesystem://server/directory/filename string. Individual elements of this string are separated by colons (:) and slashes (/).


 
Command Default

Automatically generates checkpoint name (user-checkpoint- number).

 
Command Modes

EXEC mode

 
Command History

Release
Modification

6.0(2)N1(1)

This command was introduced.

 
Usage Guidelines

Checkpoints are local to a switch. When you create a checkpoint, a snapshot of the current running configuration is stored in a checkpoint file. If you do not provide a checkpoint name, Cisco NX-OS sets the checkpoint name to user-checkpoint- number, where the number is from 1 to 10.

If Fibre Channel over Ethernet (FCoE) is enabled on the switch, you cannot restore the active configuration to the checkpoint state. The following error message appears when you create a checkpoint on a FCoE-enabled switch:

switch# checkpoint chkpoint-1
ERROR: ascii-cfg: FCOE is enabled. Disbaling rollback module (err_id 0x405F004C)
switch#
 

On a switch that has FCoE disabled, you see the following message when you create the checkpoint:

switch# checkpoint chkpoint-1
...Done
switch#
 

You can create up to ten checkpoints of your configuration per switch. When the number of checkpoints reaches the maximum limit, the oldest entry is removed.

You cannot apply the checkpoint file of one switch into another switch. You cannot start a checkpoint filename with the word system.

The checkpoint files are stored as text files that you cannot directly access or modify. When a checkpoint is cleared from the system, the associated checkpoint configuration file is deleted.

Examples

This example shows how to create a checkpoint:

switch# checkpoint
...
user-checkpoint-4 created Successfully
 
Done
switch#
 

This example shows how to create a checkpoint, named chkpnt-1, and define its purpose:

switch# checkpoint chkpnt-1 description Checkpoint to save current configuration, Sep 9 10:02 A.M.
switch#
 

This example shows how to create a checkpoint configuration file named chkpnt_configSep9-1.txt in the bootflash storage system:

switch# checkpoint file bootflash:///chkpnt_configSep9-1.txt
switch#
 

This example shows how to delete a checkpoint named chkpnt-1:

switch# no checkpoint chkpnt-1
switch#
 

 
Related Commands

Command
Description

clear checkpoint

Clears the checkpoints on the switch.

rollback

Rolls back the switch to any of the saved checkpoints.

show checkpoint all

Displays all checkpoints configured in the switch.

show checkpoint summary

Displays a summary of all checkpoints configured in the switch.

show checkpoint summary user

Displays all checkpoints created by an user.

show checkpoint system

Displays all checkpoints that were automatically created in the system.

clear aaa local user blocked

To clear the blocked local user, use the clear local user blocked command.

clear local user blocked username {all | username}

 
Syntax Description

This command has no arguments or keywords.

 
Defaults

None

 
Command Modes

Any configuration mode

 
Command History

Release
Modification

7.3(0)N1(1)

This command was introduced.

 
Usage Guidelines

None.

Examples

The following example shows how to clear all the blocked users.

switch# clear aaa local user blocked all
 

 
Related Commands

Command
Description

aaa authentication rejected

Configures the login block per user.

show aaa authentication

Displays the AAA authentication configuration.

show aaa local user blocked

Displays the blocked local users.

clear access-list counters

To clear the counters for all IPv4 access control lists (ACLs) or a single IPv4 ACL, use the clear access-list counters command.

clear access-list counters [ access-list-name ]

 
Syntax Description

access-list-name

(Optional) Name of the IPv4 ACL whose counters the switch clears. The name can be a maximum of 64 alphanumeric characters.

 
Command Default

None

 
Command Modes

EXEC mode

 
Command History

Release
Modification

6.0(2)N1(1)

This command was introduced.

Examples

This example shows how to clear counters for all IPv4 ACLs:

switch# clear access-list counters
 

This example shows how to clear counters for an IPv4 ACL named acl-ipv4-01:

switch# clear access-list counters acl-ipv4-01
 

 
Related Commands

Command
Description

access-class

Applies an IPv4 ACL to a VTY line.

ip access-group

Applies an IPv4 ACL to an interface.

ip access-list

Configures an IPv4 ACL.

show access-lists

Displays information about one or all IPv4, IPv6, and MAC ACLs.

show ip access-lists

Displays information about one or all IPv4 ACLs.

clear accounting log

To clear the accounting log, use the clear accounting log command.

clear accounting log

 
Syntax Description

This command has no arguments or keywords.

 
Command Default

None

 
Command Modes

EXEC mode

 
Command History

Release
Modification

6.0(2)N1(1)

This command was introduced.

Examples

This example shows how to clear the accounting log:

switch# clear accounting log
 

 
Related Commands

Command
Description

show accounting log

Displays the accounting log contents.

clear checkpoint database

To clear the checkpoints configured on the switch, use the clear checkpoint database command.

clear checkpoint database [ system | user ]

 
Syntax Description

system

Clears the configuration rollback checkpoint database for system checkpoints.

user

Clears the configuration rollback checkpoint database for user checkpoints.

 
Command Default

None

 
Command Modes

EXEC mode

 
Command History

Release
Modification

6.0(2)N1(1)

This command was introduced.

Examples

This example shows how to clear the configured checkpoints:

switch# clear checkpoint database
.Done
switch#
 

 
Related Commands

Command
Description

checkpoint

Creates a checkpoint.

show checkpoint

Displays all configured checkpoints.

clear ip arp

To clear the Address Resolution Protocol (ARP) table and statistics, use the clear ip arp command.

clear ip arp [ vlan vlan-id [ force-delete | vrf { vrf-name | all | default | management }]]

 
Syntax Description

vlan vlan-id

(Optional) Clears the ARP information for a specified VLAN. The range is from 1 to 4094, except for the VLANs reserved for internal use.

force-delete

(Optional) Clears the entries from ARP table without refresh.

vrf

(Optional) Specifies the virtual routing and forwarding (VRF) to clear from the ARP table.

vrf-name

VRF name. The name can be a maximum of 32 alphanumeric characters and is case sensitive.

all

Specifies that all VRF entries be cleared from the ARP table.

default

Specifies that the default VRF entry be cleared from the ARP table.

management

Specifies that the management VRF entry be cleared from the ARP table.

 
Command Default

None

 
Command Modes

Any command mode

 
Command History

Release
Modification

6.0(2)N1(1)

This command was introduced.

Examples

This example shows how to clear the ARP table statistics:

switch# clear ip arp
switch#
 

This example shows how to clear the ARP table statistics for VLAN 10 with the VRF vlan-vrf:

switch# clear ip arp vlan 10 vrf vlan-vrf
switch#
 

 
Related Commands

Command
Description

show ip arp

Displays the ARP configuration status.

clear ip arp inspection log

To clear the Dynamic ARP Inspection (DAI) logging buffer, use the clear ip arp inspection log command.

clear ip arp inspection log

 
Syntax Description

This command has no arguments or keywords.

 
Command Default

None

 
Command Modes

Any command mode

 
Command History

Release
Modification

6.0(2)N1(1)

This command was introduced.

Examples

This example shows how to clear the DAI logging buffer:

switch# clear ip arp inspection log
switch#

 
Related Commands

Command
Description

ip arp inspection log-buffer entries

Configures the DAI logging buffer size.

show ip arp inspection

Displays the DAI configuration status.

show ip arp inspection log

Displays the DAI log configuration.

show ip arp inspection statistics

Displays the DAI statistics.

clear ip arp inspection statistics vlan

To clear the Dynamic ARP Inspection (DAI) statistics for a specified VLAN, use the clear ip arp inspection statistics vlan command.

clear ip arp inspection statistics vlan vlan-list

 
Syntax Description

vlan vlan-list

Specifies the VLANs whose DAI statistics this command clears. The vlan-list argument allows you to specify a single VLAN ID, a range of VLAN IDs, or comma-separated IDs and ranges. Valid VLAN IDs are from 1 to 4094, except for the VLANs reserved for the internal switch use.

 
Command Default

None

 
Command Modes

Any command mode

 
Command History

Release
Modification

6.0(2)N1(1)

This command was introduced.

Examples

This example shows how to clear the DAI statistics for VLAN 2:

switch# clear ip arp inspection statistics vlan 2
switch#
 

This example shows how to clear the DAI statistics for VLANs 5 through 12:

switch# clear ip arp inspection statistics vlan 5-12
switch#
 

This example shows how to clear the DAI statistics for VLAN 2 and VLANs 5 through 12:

switch# clear ip arp inspection statistics vlan 2,5-12
switch#
 

 
Related Commands

Command
Description

clear ip arp inspection log

Clears the DAI logging buffer.

ip arp inspection log-buffer

Configures the DAI logging buffer size.

show ip arp inspection

Displays the DAI configuration status.

show ip arp inspection vlan

Displays DAI status for a specified list of VLANs.

clear ip dhcp snooping binding

To clear the Dynamic Host Configuration Protocol (DHCP) snooping binding database, use the clear ip dhcp snooping binding command.

clear ip dhcp snooping binding [ vlan vlan-id [ mac mac-address ip ip-address ] [ interface { ethernet slot / port | port-channel channel-number }]]

 
Syntax Description

vlan vlan-id

(Optional) Specifies the VLAN ID of the DHCP snooping binding database entry to be cleared. Valid VLAN IDs are from 1 to 4094, except for the VLANs reserved for the internal switch use.

mac-address mac-address

(Optional) Specifies the MAC address of the binding database entry to be cleared. Enter the mac-address argument in dotted hexadecimal format.

ip ip-address

(Optional) Specifies the IPv4 address of the binding database entry to be cleared. Enter the ip-address argument in dotted decimal format.

interface

(Optional) Specifies the Ethernet or EtherChannel interface.

ethernet slot / port

(Optional) Specifies the Ethernet interface of the binding database entry to be cleared.

port-channel channel-number

(Optional) Specifies the Ethernet port channel of the binding database entry to be cleared.

 
Command Default

None

 
Command Modes

Any command mode

 
Command History

Release
Modification

6.0(2)N1(1)

This command was introduced.

Examples

This example shows how to clear the DHCP snooping binding database:

switch# clear ip dhcp snooping binding
switch#
 

This example shows how to clear a specific entry from the DHCP snooping binding database:

switch# clear ip dhcp snooping binding vlan 23 mac 0060.3aeb.54f0 ip 10.34.54.9 interface ethernet 2/11
switch#
 

 
Related Commands

Command
Description

copy running-config startup-config

Copies the running configuration to the startup configuration.

show ip dhcp snooping binding

Displays IP-MAC address bindings, including the static IP source entries.

show running-config dhcp

Displays DHCP snooping configuration, including the IP Source Guard configuration.

clear ip dhcp snooping statistics

To clear the Dynamic Host Configuration Protocol (DHCP) snooping statistics, use the clear ip dhcp snooping statistics command.

clear ip dhcp snooping statistics

 
Syntax Description

This command has no arguments or keywords.

 
Command Default

None

 
Command Modes

Any command mode

 
Command History

Release
Modification

6.0(2)N1(1)

This command was introduced.

Examples

This example shows how to clear the DHCP snooping statistics:

switch# clear ip dhcp snooping statistics
switch#
 

 
Related Commands

Command
Description

copy running-config startup-config

Copies the running configuration to the startup configuration.

show ip dhcp snooping statistics

Displays DHCP snooping statistics.

show running-config dhcp

Displays DHCP snooping configuration, including the IP Source Guard configuration.

clear ipv6 dhcp-ldra statistics

To clear Lightweight DHCPv6 Relay Agent (LDRA) related statistics, use the clear ipv6 dhcp-ldra statistics command.

clear ipv6 dhcp-ldra statistics

 
Syntax Description

This command has no arguments or keywords.

 
Defaults

None

 
Command Modes

Any configuration mode

 
Command History

Release
Modification

7.3(0)N1(1)

This command was introduced.

 
Usage Guidelines

To use this command, you must enable the DHCP feature and LDRA feature.

Examples

This example shows how to clear the LDRA related statistics:

 
switch# clear ipv6 dhcp-ldra statistics

 

 
Related Commands

Command
Description

show ipv6 dhcp-ldra

Displays the configuration details of LDRA.