Contents

• Logging Services Commands

• archive-length

• archive-size

• clear logging

• device

• file-size

• frequency (logging)

• logging

• logging archive

• logging buffered

• logging console

• logging disable

• logging events link-status

• logging events link-status (interface)

• logging facility

• logging history

• logging history size

• logging hostnameprefix

• logging localfilesize

• logging monitor

• logging source-interface

• logging suppress deprecated

• logging suppress duplicates

• logging trap

• service timestamps

• severity

• show logging

• show logging history

• terminal monitor (logging)

Logging Services Commands

---

This module describes the Cisco IOS XR software commands to configure system logging (syslog) for system monitoring on the router.

For detailed information about logging concepts, configuration tasks, and examples, see the Implementing Logging Services module in the Cisco IOS XR System Monitoring Configuration Guide for the Cisco XR 12000 Series Router.

For alarm management and logging correlation commands, see the Alarm Management and Logging Correlation Commands module in the Cisco IOS XR System Monitoring Command Reference for the Cisco XR 12000 Series Router.

For detailed information about alarm and logging correlation concepts, configuration tasks, and examples, see the Implementing Alarm Logs and Logging Correlation module in the Cisco IOS XR System Monitoring Configuration Guide for the Cisco XR 12000 Series Router.

• archive-length
• archive-size
• clear logging
• device
• file-size
• frequency (logging)
• logging
• logging archive
• logging buffered
• logging console
• logging disable
• logging events link-status
• logging events link-status (interface)
• logging facility
• logging history
• logging history size
• logging hostnameprefix
• logging localfilesize
• logging monitor
• logging source-interface
• logging suppress deprecated
• logging suppress duplicates
• logging trap
• service timestamps
• severity
• show logging
• show logging history
• terminal monitor (logging)

archive-length

To specify the length of time that logs are maintained in the logging archive, use the archive-length command in logging archive configuration mode. To return to the default, use the no form of this command.

archive-length weeks

no archive-length

Syntax Description

weeks

Length of time (in weeks) that logs are maintained in the archive. Range is 0 to 4294967295.

Command Default

weeks: 4 weeks

Command Modes

Logging archive configuration

Command History

Release	Modification
Release 3.2	This command was introduced.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

Use the archive-length command to specify the maximum number of weeks that the archive logs are maintained in the archive. Any logs older than this number are automatically removed from the archive.

Task ID

Task ID	Operations
logging	read, write

Examples

The following example shows how to set the log archival period to 6 weeks:

RP/0/0/CPU0:router/CPU0:router(config)# logging archive
RP/0/0/CPU0:router/CPU0:router(config-logging-arch)#archive-length 6 

archive-size

To specify the amount of space allotted for syslogs on a device, use the archive-size command in logging archive configuration mode. To return to the default, use the no form of this command.

archive-size size

no archive-size

Syntax Description

size	Amount of space (in MB) allotted for syslogs. The range is 0 to 2047.

Command Default

size: 20 MB

Command Modes

Logging archive configuration

Command History

Release	Modification
Release 3.2	This command was introduced.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

Use the archive-length command to specify the maximum total size of the syslog archives on a storage device. If the size is exceeded then the oldest file in the archive is deleted to make space for new logs.

Task ID

Task ID	Operations
logging	read, write

Examples

The following example shows how to set the allotted space for syslogs to 50 MB:

RP/0/0/CPU0:router(config)# logging archive
RP/0/0/CPU0:router(config-logging-arch)# archive-size 50

clear logging

To clear system logging (syslog) messages from the logging buffer, use the clear logging command in EXEC mode.

clear logging

Syntax Description

This command has no arguments or keywords.

Command Default

No default behavior or values

Command Modes

EXEC

Command History

Release	Modification
Release 3.2	This command was supported.
Release 3.7.0	Removed the internal keyword.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

Use the clear logging command to empty the contents of the logging buffer. When the logging buffer becomes full, new logged messages overwrite old messages.

Use the logging buffered command to specify the logging buffer as a destination for syslog messages, set the size of the logging buffer, and limit syslog messages sent to the logging buffer based on severity.

Use the show logging command to display syslog messages stored in the logging buffer.

Task ID

Task ID	Operations
logging	execute

Examples

The following example shows how to clear the logging buffer:

RP/0/0/CPU0:router# clear logging

Clear logging buffer [confirm] [y/n] :y

Related Commands

Command	Description
logging buffered	Specifies the logging buffer as a destination for syslog messages, sets the size of the logging buffer, and limits syslog messages sent to the logging buffer based on severity.
show logging	Displays syslog messages stored in the logging buffer.

device

To specify the device to be used for logging syslogs, use the device command in logging archive configuration mode. To return to the default, use the no form of this command.

device { disk0 | disk1 | harddisk }

no device

Syntax Description

disk0	Uses disk0 as the archive device.
disk1	Uses disk1 as the archive device.
harddisk	Uses the harddisk as the archive device.

Command Default

No default behavior or values

Command Modes

Logging archive configuration

Command History

Release	Modification
Release 3.2	This command was introduced.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

Use the device command to specify where syslogs are logged. The logs are created under the directory <device>/var/log. If the device is not configured, then all other logging archive configurations are rejected. Similarly, the configured device cannot be removed until the other logging archive configurations are removed.

We recommend that syslogs be archived to the harddisk because it has more capacity.

Task ID

Task ID	Operations
logging	read, write

Examples

The following example shows how to specify disk1 as the device for logging syslog messages:

RP/0/0/CPU0:router(config)# logging archive
RP/0/0/CPU0:router(config-logging-arch)# device disk1

file-size

To specify the maximum file size for a log file in the archive, use the file-size command in logging archive configuration mode. To return to the default, use the no form of this command.

file-size size

no file-size

Syntax Description

size	Maximum file size (in MB) for a log file in the logging archive. The range is 1 to 2047.

Command Default

size: 1 MB

Command Modes

Logging archive configuration

Command History

Release	Modification
Release 3.2	This command was introduced.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

Use the file-size command to specify the maximum file size that a single log file in the archive can grow to. Once this limit is reached, a new file is automatically created with an increasing serial number.

Task ID

Task ID	Operations
logging	read, write

Examples

The following example shows how to set the maximum log file size to 10 MB:

RP/0/0/CPU0:router(config)# logging archive
RP/0/0/CPU0:router(config-logging-arch)# file-size 10

frequency (logging)

To specify the collection period for logs, use the frequency command in logging archive configuration mode. To return to the default, use the no form of this command.

frequency { daily | weekly }

no frequency

Syntax Description

daily	Logs are collected daily.
weekly	Logs are collected weekly.

Command Default

Logs are collected daily.

Command Modes

Logging archive configuration

Command History

Release	Modification
Release 3.2	This command was introduced.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

Use the frequency command to specify if logs are collected daily or weekly.

Task ID

Task ID	Operations
logging	read, write

Examples

The following example shows how to specify that logs are collected weekly instead of daily:

RP/0/0/CPU0:router(config)# logging archive
RP/0/0/CPU0:router(config-logging-arch)# frequency weekly

logging

To specify a system logging (syslog) server host as the recipient of syslog messages, use the logging command in global configuration mode. To remove the logging command from the configuration file and delete a syslog server from the list of syslog server hosts, use the no form of this command.

logging { ip-address | hostname }

no logging { ip-address | hostname }

Syntax Description

ip-address | hostname

IP address or hostname of the host to be used as a syslog server.

Command Default

No syslog server hosts are configured as recipients of syslog messages.

Command Modes

Global configuration

Command History

Release	Modification
Release 3.2	This command was introduced.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

Use the logging command to identify a syslog server host to receive messages. By issuing this command more than once, you build a list of syslog servers that receive messages.

When syslog messages are sent to a syslog server, the Cisco IOS XR software includes a numerical message identifier in syslog messages. The message identifier is cumulative and sequential. The numerical identifier included in syslog messages sent to syslog servers provides a means to determine if any messages have been lost.

Use the logging trap command to limit the syslog messages sent to syslog servers based on severity.

Task ID

Task ID	Operations
logging	read, write

Examples

The following example shows how to log messages to a host named host1:

RP/0/0/CPU0:router(config)# logging host1

Related Commands

Command	Description
logging trap	Limits the syslog messages sent to syslog servers based on severity.

logging archive

To configure attributes for archiving syslogs, use the logging archive command in global configuration mode. To exit the logging archive submode, use the no form of this command.

logging archive

no logging archive

Syntax Description

This command has no arguments or keywords.

Command Default

No default behavior or values

Command Modes

Global configuration

Command History

Release	Modification
Release 3.2	This command was introduced.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

Use the logging archive command to configure attributes for archiving syslogs. This command enters logging archive configuration mode and allows you to configure the commands in Table 1:

Note	The configuration attributes must be explicitly configured in order to use the logging archive feature.

Table 1 Configuring Command Attributes For Archiving Syslogs

Command	Range	Description	Recommended Setting
archive-length	<0-4294967295>	Number of weeks	4 weeks
archive-size	<1-2047>	Size in MB	20 MB
device	<disk0 | disk1 | harddisk>	Use configured devices as the archive device.	harddisk
file size	<1-2047>	Size in MB	1 MB
frequency	<daily | weekly>		daily
severity	<alerts | critical | debugging | emergencies | errors | informational | notifications | warnings>		informational

Task ID

Task ID	Operations
logging	read, write

Examples

The following example shows how to enter logging archive configuration mode and change the device to be used for logging syslogs to disk1:

RP/0/0/CPU0:router(config)# logging archive
RP/0/0/CPU0:router(config-logging-arch)# device disk1

logging buffered

To specify the logging buffer as a destination for system logging (syslog) messages, use the logging buffered command in global configuration mode. To remove the logging buffered command from the configuration file and cancel the use of the buffer, use the no form of this command.

logging buffered { size | severity }

no logging buffered { size | severity }

Syntax Description

size	Size of the buffer, in bytes. Range is 307200 to 125000000 bytes. The default is 307200 bytes.
severity	Severity level of messages that display on the console. Possible severity levels and their respective system conditions are listed under Table 1in the “Usage Guidelines” section. The default is debugging.

Command Default

size: 307200 bytes

severity: debugging

Command Modes

Global configuration

Command History

Release	Modification
Release 3.2	This command was introduced.
Release 4.0.0	The value of size argument is changed from 4096 to 307200.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

Use the logging buffered command to copy messages to the logging buffer. The logging buffer is circular, so newer messages overwrite older messages after the buffer is filled. This command is related to the show logging buffer command, which means that when you execute a logging buffered warnings command, it enables the logging for all the levels below the configured level, including log for LOG_ERR, LOG_CRIT, LOG_ALERT, LOG_EMERG, and LOG_WARNING messages. Use the logging buffer size to change the size of the buffer.

The value specified for the severity argument causes messages at that level and at numerically lower levels to be displayed on the console terminal. See Table 1for a list of the possible severity level keywords for the severity argument.

This table describes the acceptable severity levels for the severity argument.

Table 2 Severity Levels for Messages

Level Keywords	Level	Description	Syslog Definition
emergencies	0	Unusable system	LOG_EMERG
alerts	1	Need for immediate action	LOG_ALERT
critical	2	Critical condition	LOG_CRIT
errors	3	Error condition	LOG_ERR
warnings	4	Warning condition	LOG_WARNING
notifications	5	Normal but significant condition	LOG_NOTICE
informational	6	Informational message only	LOG_INFO
debugging	7	Debugging message	LOG_DEBUG

Task ID

Task ID	Operations
logging	read, write

Examples

The following example shows how to set the severity level of syslog messages logged to the buffer to notifications:

RP/0/0/CPU0:router(config)# logging buffered notifications

Related Commands

Command	Description
archive-size	Clears messages from the logging buffer.
show logging	Displays syslog messages stored in the logging buffer.

logging console

To enable logging of system logging (syslog) messages logged to the console by severity level, use the logging console command in global configuration mode. To return console logging to the default setting, use the no form of this command.

logging console { severity | disable }

no logging console

Syntax Description

severity	Severity level of messages logged to the console, including events of a higher severity level (numerically lower). The default is informational. Settings for the severity levels and their respective system conditions are listed in Table 1 under the “Usage Guidelines” section for the logging buffered command.
disable	Removes the logging console command from the configuration file and disables logging to the console terminal.

Command Default

By default, logging to the console is enabled.

severity: informational

Command Modes

Global configuration

Command History

Release	Modification
Release 3.2	This command was introduced.
Release 3.3.0	Added the disable keyword. The command no logging console was changed to reset console logging to the default setting.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

Use the logging console command to prevent debugging messages from flooding your screen.

The logging console is for the console terminal. The value specified for the severity argument causes messages at that level and at numerically lower levels (higher severity levels) to be displayed on the console.

Use the logging console disable command to disable console logging completely.

Use the no logging console command to return the configuration to the default setting.

Use the show logging command to display syslog messages stored in the logging buffer.

Task ID

Task ID	Operations
logging	read, write

Examples

The following example shows how to change the level of messages displayed on the console terminal to alerts (1), which means that alerts (1) and emergencies (0) are displayed:

RP/0/0/CPU0:router(config)# logging console alerts

The following example shows how to disable console logging:

RP/0/0/CPU0:router(config)# logging console disable

The following example shows how to return console logging to the default setting (the console is enabled, severity: informational):

RP/0/0/CPU0:router(config)# no logging console 

Related Commands

Command	Description
show logging	Displays syslog messages stored in the logging buffer.

logging disable

To disable logging of system logging (syslog) messages, use the logging disable command in global configuration mode. To return logging to the default setting, use the no form of this command.

logging disable

no logging disable

Syntax Description

This command has no arguments or keywords.

Command Default

By default, logging is enabled.

Command Modes

Global configuration

Command History

Release	Modification
Release 3.3.0	This command was introduced.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

Use the logging disable command to disable logging completely.

Use the no logging disable command to return the configuration to the default setting.

Task ID

Task ID	Operations
logging	read, write

Examples

The following example shows how to disable syslog messages:

RP/0/0/CPU0:router(config)# logging disable

logging events link-status

To enable the logging of link-status system logging (syslog) messages for logical and physical links, use the logging events link-status command in global configuration mode. To disable the logging of link status messages, use the no form of this command.

logging events link-status { disable | software-interfaces }

no logging events link-status [ disable | software-interfaces ]

Syntax Description

disable	Disables the logging of link-status messages for all interfaces, including physical links.
software-interfaces	Enables the logging of link-status messages for logical links as well as physical links.

Command Default

The logging of link-status messages is enabled for physical links.

Command Modes

Global configuration

Command History

Release	Modification
Release 3.2	This command was introduced.
Release 3.5.0	The logical and physical keywords were replaced by the software-interfaces and disable keywords.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

When the logging of link-status messages is enabled, the router can generate a high volume of link-status up and down system logging messages.

Use the no logging events link-status command to enable the logging of link-status messages for physical links only, which is the default behavior.

Note	Enabling the logging events link-status (interface) command on a specific interface overrides the global configuration set using the logging events link-status command described in this section.

Task ID

Task ID	Operations
logging	read, write

Examples

The following example shows how to disable the logging of physical and logical link-status messages:

RP/0/0/CPU0:router(config)# logging events link-status disable

Related Commands

Command	Description
logging events link-status (interface)	Enables the logging of link-status system logging (syslog) messages on a specific interface for virtual interfaces and subinterfaces.

logging events link-status (interface)

To enable the logging of link-status system logging (syslog) messages on a specific interface for virtual interfaces and subinterfaces, use the logging events link-status command in the appropriate interface or subinterface mode. To disable the logging of link status messages, use the no form of this command.

logging events link-status

no logging events link-status

Syntax Description

This command has no arguments or keywords.

Command Default

The logging of link-status messages is disabled for virtual interfaces and subinterfaces.

Command Modes

Interface configuration

Command History

Release	Modification
Release 3.2	This command was introduced.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

When the logging of link-status messages is enabled, the router can generate a high volume of link-status up and down system logging messages. The logging events link-status command enables messages for virtual interfaces and subinterfaces only.

The logging events link-status command allows you to enable and disable logging on a specific interface for bundles, tunnels, and VLANs.

Use the no logging events link-status command to disable the logging of link-status messages.

Note	Enabling the logging events link-status command on a specific interface overrides the global configuration set using the logging events link-status command in global configuration mode.

Task ID

Task ID	Operations
logging	read, write

Examples

The following example shows the results of turning on logging for a bundle interface:

RP/0/0/CPU0:router(config)# int bundle-pos 1 
RP/0/0/CPU0:router(config-if)# logging events link-status
RP/0/0/CPU0:router(config-if)# no shutdown 
RP/0/0/CPU0:router(config-if)# commit
LC/0/4/CPU0:Jun 29 12:51:26.887 : ifmgr[142]: 
%PKT_INFRA-LINK-3-UPDOWN : Interface POS0/4/0/0, changed state to Up 
LC/0/4/CPU0:Jun 29 12:51:26.897 : ifmgr[142]: 
%PKT_INFRA-LINEPROTO-6-UPDOWN : Line protocol on Interface 
POS0/4/0/0, changed state to Up 
RP/0/0/CPU0:router(config-if)# 
RP/0/0/CPU0:router(config-if)# shutdown 
RP/0/0/CPU0:router(config-if)# commit 
LC/0/4/CPU0:Jun 29 12:51:32.375 : ifmgr[142]: 
%PKT_INFRA-LINK-3-UPDOWN : Interface POS0/4/0/0, changed 
state to Down 
LC/0/4/CPU0:Jun 29 12:51:32.376 : ifmgr[142]: 
%PKT_INFRA-LINEPROTO-6-UPDOWN : Line protocol on Interface 
POS0/4/0/0, changed state to Down 
RP/0/0/CPU0:router(config-if)# 

The following example shows a sequence of commands for a tunnel interface with and without logging turned on:

RP/0/0/CPU0:router(config)# int tunnel-te 1 
RP/0/0/CPU0:router(config-if)# commit 
RP/0/0/CPU0:router(config-if)# shutdown 
RP/0/0/CPU0:router(config-if)# commit 
RP/0/0/CPU0:router(config-if)# no shutdown 
RP/0/0/CPU0:router(config-if)# commit 
RP/0/0/CPU0:router(config-if)# logging events link-status 
RP/0/0/CPU0:router(config-if)# commit 
RP/0/0/CPU0:router(config-if)# shutdown 
RP/0/0/CPU0:router(config-if)# commit 
RP/0/0/CPU0:Jun 29 14:05:57.732 : ifmgr[176]: 
%PKT_INFRA-LINK-3-UPDOWN : Interface tunnel-te1, changed 
state to Administratively Down 
RP/0/0/CPU0:Jun 29 14:05:57.733 : ifmgr[176]: 
%PKT_INFRA-LINEPROTO-6-UPDOWN : Line protocol on Interface 
tunnel-te1, changed state to Administratively Down 
RP/0/0/CPU0:router(config-if)# no shutdown 
RP/0/0/CPU0:router(config-if)# commit 
RP/0/0/CPU0:Jun 29 14:06:02.104 : ifmgr[176]: 
%PKT_INFRA-LINK-3-UPDOWN : Interface tunnel-te1, changed 
state to Down 
RP/0/0/CPU0:Jun 29 14:06:02.109 : ifmgr[176]: 
%PKT_INFRA-LINEPROTO-6-UPDOWN : Line protocol on Interface 
tunnel-te1, changed state to Down 

The following example shows the same process for a subinterface:

RP/0/0/CPU0:router(config)# int gigabitEthernet 0/5/0/0.1 
RP/0/0/CPU0:router(config-subif)# commit 
RP/0/0/CPU0:router(config-subif)# shutdown 
RP/0/0/CPU0:router(config-subif)# commit 
RP/0/0/CPU0:router(config-subif)# no shutdown 
RP/0/0/CPU0:router(config-subif)# commit 
RP/0/0/CPU0:router(config-subif)# logging events link-status 
RP/0/0/CPU0:router(config-subif)# commit 
RP/0/0/CPU0:router(config-subif)# shutdown 
RP/0/0/CPU0:router(config-subif)# commit 
LC/0/5/CPU0:Jun 29 14:06:46.710 : ifmgr[142]: 
%PKT_INFRA-LINEPROTO-6-UPDOWN : Line protocol on Interface 
GigabitEthernet0/5/0/0.1, changed state to Administratively Down 
LC/0/5/CPU0:Jun 29 14:06:46.726 : ifmgr[142]: 
%PKT_INFRA-LINK-3-UPDOWN : Interface 
GigabitEthernet0/5/0/0.1, changed state to Administratively Down 
RP/0/0/CPU0:router(config-subif)# no shutdown 
RP/0/0/CPU0:router(config-subif)# commit 
LC/0/5/CPU0:Jun 29 14:06:52.229 : ifmgr[142]: 
%PKT_INFRA-LINK-3-UPDOWN : Interface 
GigabitEthernet0/5/0/0.1, changed state to Up 
LC/0/5/CPU0:Jun 29 14:06:52.244 : ifmgr[142]: 
%PKT_INFRA-LINEPROTO-6-UPDOWN : Line protocol on Interface 
GigabitEthernet0/5/0/0.1, changed state to Down 
RP/0/0/CPU0:router(config-subif)# 

logging facility

To configure the type of syslog facility in which system logging (syslog) messages are sent to syslog servers, use the logging facility command in global configuration mode. To remove the logging facility command from the configuration file and disable the logging of messages to any facility type, use the no form of this command.

logging facility [type]

no logging facility

Syntax Description

type	(Optional) Syslog facility type. The default is local7. Possible values are listed under Table 1in the “Usage Guidelines” section.

Command Default

type: local7

Command Modes

Global configuration

Command History

Release	Modification
Release 3.2	This command was introduced.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

This table describes the acceptable options for the type argument.

Table 3 Facility Type Descriptions 

Facility Type	Description
auth	Authorization system
cron	Cron/at facility
daemon	System daemon
kern	Kernel
local0	Reserved for locally defined messages
local1	Reserved for locally defined messages
local2	Reserved for locally defined messages
local3	Reserved for locally defined messages
local4	Reserved for locally defined messages
local5	Reserved for locally defined messages
local6	Reserved for locally defined messages
local7	Reserved for locally defined messages
lpr	Line printer system
mail	Mail system
news	USENET news
sys9	System use
sys10	System use
sys11	System use
sys12	System use
sys13	System use
sys14	System use
syslog	System log
user	User process
uucp	UNIX-to-UNIX copy system

Use the logging command to specify a syslog server host as a destination for syslog messages.

Task ID

Task ID	Operations
logging	read, write

Examples

The following example shows how to configure the syslog facility to the kern facility type:

RP/0/0/CPU0:router(config)# logging facility kern

Related Commands

Command	Description
logging	Specifies a syslog server host as a destination for syslog messages.

logging history

To change the severity level of system logging (syslog) messages sent to the history table on the router and a Simple Network Management Protocol (SNMP) network management station (NMS), use the logging history command in global configuration mode. To remove the logging history command from the configuration and return the logging of messages to the default level, use the no form of this command.

logging history severity

no logging history

Syntax Description

severity

Severity level of messages sent to the history table on the router and an SNMP NMS, including events of a higher severity level (numerically lower). Settings for the severity levels and their respective system conditions are listed in Table 1 under the “Usage Guidelines” section for the logging buffered command.

Command Default

severity: warnings

Command Modes

Global configuration

Command History

Release	Modification
Release 3.2	This command was introduced.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

Logging of messages to an SNMP NMS is enabled by the snmp-server enable traps command. Because SNMP traps are inherently unreliable and much too important to lose, at least one syslog message, the most recent message, is stored in a history table on the router.

Use the logging history command to reflect the history of last 500 syslog messages. For example, when this command is issued, the last 500 syslog messages with severity less than warning message are displayed in the output of show logging history command.

Use the show logging history command to display the history table, which contains table size, message status, and message text data.

Use the logging history size command to change the number of messages stored in the history table.

The value specified for the severity argument causes messages at that severity level and at numerically lower levels to be stored in the history table of the router and sent to the SNMP NMS. Severity levels are numbered 0 to 7, with 1 being the most important message and 7 being the least important message (that is, the lower the number, the more critical the message). For example, specifying the level critical with the critical keyword causes messages at the severity level of critical (2), alerts (1), and emergencies (0) to be stored in the history table and sent to the SNMP NMS.

The no logging history command resets the history level to the default.

Task ID

Task ID	Operations
logging	read, write

Examples

The following example shows how to change the level of messages sent to the history table and to the SNMP server to alerts (1), which means that messages at the severity level of alerts (1) and emergencies (0) are sent:

RP/0/0/CPU0:router(config)# logging history alerts

Related Commands

Command	Description
logging history size	Changes the number of messages stored in the history table.
show logging history	Displays information about the state of the syslog history table.
snmp-server enable traps	Enables SNMP trap notifications.

logging history size

To change the number of system logging (syslog) messages that can be stored in the history table, use the logging history size command in global configuration mode. To remove the logging history size command from the configuration and return the number of messages to the default value, use the no form of this command.

logging history size number

no logging history number

Syntax Description

number

Number from 1 to 500 indicating the maximum number of messages that can be stored in the history table. The default is 1 message.

Command Default

number: 1 message

Command Modes

Global configuration

Command History

Release	Modification
Release 3.2	This command was introduced.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

Use the logging history size command to change the number of messages that can be stored in this history table. When the history table is full (that is, when it contains the maximum number of messages specified with the command), the oldest message is deleted from the table to allow the new message to be stored.

Use the logging history command to change the severity level of syslog messages stored in the history file and sent to the SNMP server.

Task ID

Task ID	Operations
logging	read, write

Examples

The following example shows how to set the number of messages stored in the history table to 20:

RP/0/0/CPU0:router(config)# logging history size 20

Related Commands

Command	Description
logging history	Changes the severity level of syslog messages stored in the history file and sent to the SNMP server.
show logging history	Displays information about the state of the syslog history table.

logging hostnameprefix

To append a hostname prefix to system logging (syslog) messages logged to syslog servers, use the logging hostnameprefix command in global configuration mode. To remove the logging hostnameprefix command from the configuration file and disable the logging host name prefix definition, use the no form of this command.

logging hostnameprefix hostname

no logging hostnameprefix

Syntax Description

hostname

Hostname that appears in messages sent to syslog servers.

Command Default

No hostname prefix is added to the messages logged to the syslog servers.

Command Modes

Global configuration

Command History

Release	Modification
Release 3.2	This command was introduced.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

Use the logging hostnameprefix command to append a hostname prefix to messages sent to syslog servers from the router. You can use these prefixes to sort the messages being sent to a given syslog server from different networking devices.

Use the logging command to specify a syslog server host as a destination for syslog messages.

Task ID

Task ID	Operations
logging	read, write

Examples

The following example shows how to add the hostname prefix host1 to messages sent to the syslog servers from the router:

RP/0/0/CPU0:router(config)# logging hostnameprefix host1

Related Commands

Command	Description
hostname	Specifies or modifies the network name of the networking device.
logging	Specifies a syslog server host as a destination for syslog messages.

logging localfilesize

To specify the size of the local logging file, use the logging localfilesize command in global configuration mode. To remove the logging localfilesize command from the configuration file and restore the system to the default condition, use the no form of this command.

logging localfilesize bytes

no logging localfilesize bytes

Syntax Description

bytes

Size of the local logging file in bytes. Range is 0 to 4294967295. Default is 32000 bytes.

Command Default

bytes: 32000 bytes

Command Modes

Global configuration

Command History

Release	Modification
Release 3.2	This command was introduced.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

Use the logging localfilesize command to set the size of the local logging file.

Task ID

Task ID	Operations
logging	read, write

Examples

This example shows how to set the local logging file to 90000 bytes:

RP/0/0/CPU0:router(config)# logging localfilesize 90000

Related Commands

Command	Description
show logging	Displays syslog messages stored in the logging buffer.

logging monitor

To specify terminal lines other than the console terminal as destinations for system logging (syslog) messages and limit the number of messages sent to terminal lines based on severity, use the logging monitor command in global configuration mode. To remove the logging monitor command from the configuration file and disable logging to terminal lines other than the console line, use the no form of this command.

logging monitor [severity]

no logging monitor

Syntax Description

severity

(Optional) Severity level of messages logged to the terminal lines, including events of a higher severity level (numerically lower). The default is debugging. Settings for the severity levels and their respective system conditions are listed under Table 1 in the “Usage Guidelines” section for the logging buffered command.

Command Default

severity: debugging

Command Modes

Global configuration

Command History

Release	Modification
Release 3.2	This command was introduced.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

The logging monitor is for the terminal monitoring. Use the logging monitor command to restrict the messages displayed on terminal lines other than the console line (such as virtual terminals). The value set for the severity argument causes messages at that level and at numerically lower levels to be displayed on the monitor.

Use the terminal monitor (logging) command to enable the display of syslog messages for the current terminal session.

Task ID

Task ID	Operations
logging	read, write

Examples

The following example shows how to set the severity level of messages logged to terminal lines to errors:

RP/0/0/CPU0:router(config)# logging monitor errors

Related Commands

Command	Description
terminal monitor (logging)	Enables the display of syslog messages for the current terminal session.

logging source-interface

To set all system logging (syslog) messages being sent to syslog servers to contain the same IP address, regardless of which interface the syslog message uses to exit the router, use the logging source-interface command in global configuration mode. To remove the logging source-interface command from the configuration file and remove the source designation, use the no form of this command.

logging source-interface type interface-path-id

no logging source-interface

Syntax Description

type	Interface type. For more information, use the question mark (?) online help function.
interface-path-id	Physical interface or virtual interface. Note    Use the show interfaces command to see a list of all interfaces currently configured on the router. For more information about the syntax for the router, use the question mark (?) online help function.

Command Default

No source IP address is specified.

Command Modes

Global configuration

Command History

Release	Modification
Release 3.2	This command was introduced.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

Normally, a syslog message contains the IP address of the interface it uses to leave the networking device. Use the logging source-interface command to specify that syslog packets contain the IP address of a particular interface, regardless of which interface the packet uses to exit the networking device.

Use the logging command to specify a syslog server host as a destination for syslog messages.

Task ID

Task ID	Operations
logging	read, write

Examples

The following example shows how to specify that the IP address for Packet-over-SONET/SDH (POS) interface 0/1/0/1 be set as the source IP address for all messages:

RP/0/0/CPU0:router(config)# logging source-interface pos 0/1/0/1

Related Commands

Command	Description
logging	Specifies a syslog server host as a destination for syslog messages.

logging suppress deprecated

To prevent the logging of messages to the console to indicate that commands are deprecated, use the logging suppress deprecated command in global configuration mode. To remove the logging suppress deprecated command from the configuration file, use the no form of this command.

logging suppress deprecated

no logging suppress deprecated

Syntax Description

This command has no arguments or keywords.

Command Default

Console messages are displayed when deprecated commands are used.

Command Modes

Global configuration

Command History

Release	Modification
Release 3.5.0	This command was introduced.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

The logging suppress deprecated command affects messages to the console only.

Task ID

Task ID	Operations
logging	read, write

Examples

The following example shows how to suppress the consecutive logging of deprecated messages:

RP/0/0/CPU0:router(config)# logging suppress deprecate

logging suppress duplicates

To prevent the consecutive logging of more than one copy of the same system logging (syslog) message, use the logging suppress duplicates command in global configuration mode. To remove the logging suppress duplicates command from the configuration file and disable the filtering process, use the no form of this command.

logging suppress duplicates

no logging suppress duplicates

Syntax Description

This command has no arguments or keywords.

Command Default

Duplicate messages are logged.

Command Modes

Global configuration

Command History

Release	Modification
Release 3.2	This command was introduced.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

If you use the logging suppress duplicates command during debugging sessions, you might not see all the repeated messages and could miss important information related to problems that you are attempting to isolate and resolve. In such a situation, you might consider disabling this command.

Task ID

Task ID	Operations
logging	read, write

Examples

The following example shows how to suppress the consecutive logging of duplicate messages:

RP/0/0/CPU0:router(config)# logging suppress duplicates

Related Commands

Command	Description
logging	Specifies a syslog server host as a destination for syslog messages.
logging buffered	Specifies the logging buffer as a destination for syslog messages, sets the size of the logging buffer, and limits the syslog messages sent to the logging buffer based on severity.
logging monitor	Specifies terminal lines other than the console terminal as destinations for syslog messages and limits the number of messages sent to terminal lines based on severity.

logging trap

To specify the severity level of messages logged to system logging (syslog) servers, use the logging trap command in global configuration mode. To restore the default behavior, use the no form of this command.

logging trap [severity]

no logging trap

Syntax Description

severity

(Optional) Severity level of messages logged to the syslog servers, including events of a higher severity level (numerically lower). The default is informational. Settings for the severity levels and their respective system conditions are listed under Table 1 in the “Usage Guidelines” section for the logging buffered command.

Command Default

severity: informational

Command Modes

Global configuration

Command History

Release	Modification
Release 3.2	This command was introduced.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

Use the logging trap command to limit the logging of messages sent to syslog servers to only those messages at the specified level.

Table 1 under the “Usage Guidelines” section for the logging buffered command lists the syslog definitions that correspond to the debugging message levels.

Use the logging command to specify a syslog server host as a destination for syslog messages.

Task ID

Task ID	Operations
logging	read, write

Examples

The following example shows how to restrict messages to notifications (5) and numerically lower levels.

RP/0/0/CPU0:router(config)# logging trap notifications

Related Commands

Command	Description
logging	Specifies a syslog server host as a destination for syslog messages.

service timestamps

To modify the time-stamp format for system logging (syslog) and debug messages, use the service timestamps command in global configuration mode. To revert to the default timestamp format, use the no form of this command.

service timestamps [ [ debug | log ] { datetime [localtime] [msec] [show-timezone] | disable | uptime } ]

no service timestamps [ [ debug | log ] { datetime [localtime] [msec] [show-timezone] | disable | uptime } ]

Syntax Description

debug	(Optional) Specifies the time-stamp format for debugging messages.
log	(Optional) Specifies the time-stamp format for syslog messages.
datetime	(Optional) Specifies that syslog messages are time-stamped with date and time.
localtime	(Optional) When used with the datetime keyword, includes the local time zone in time stamps.
msec	(Optional) When used with the datetime keyword, includes milliseconds in the time stamp.
show-timezone	(Optional) When used with the datetime keyword, includes time zone information in the time stamp.
disable	(Optional) Causes messages to be time-stamped in the default format.
uptime	(Optional) Specifies that syslog messages are time-stamped with the time that has elapsed since the networking device last rebooted.

Command Default

Messages are time-stamped in the month day hh:mm:ss by default.

The default for the service timestamps debug datetime and service timestamps log datetime forms of the command with no additional keywords is to format the time in Coordinated Universal Time (UTC) without milliseconds and time zone information.

Command Modes

Global configuration

Command History

Release	Modification
Release 3.2	This command was introduced.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

Time stamps can be added to either debugging or syslog messages independently. The uptime keyword adds time stamps in the format hhhh:mm:ss, indicating the elapsed time in hours:minutes:seconds since the networking device last rebooted. The datetime keyword adds time stamps in the format mmm dd hh:mm:ss, indicating the date and time according to the system clock. If the system clock has not been set, the date and time are preceded by an asterisk (*), which indicates that the date and time have not been set and should be verified.

The no form of the service timestamps command causes messages to be time-stamped in the default format.

Entering the service timestamps form of this command without any keywords or arguments is equivalent to issuing the service timestamps debug uptime form of this command.

Task ID

Task ID	Operations
logging	read, write

Examples

The following example shows how to enable time stamps on debugging messages, which show the elapsed time since the networking device last rebooted:

RP/0/0/CPU0:router(config)# service timestamps debug uptime

The following example shows how to enable time stamps on syslog messages, which show the current time and date relative to the local time zone, with the time zone name included:

RP/0/0/CPU0:router(config)# service timestamps log datetime localtime show-timezone

severity

To specify the filter level for logs, use the severity command in logging archive configuration mode. To return to the default, use the no form of this command.

severity { severity }

no severity

Syntax Description

severity

Severity level for determining which messages are logged to the archive. Possible severity levels and their respective system conditions are listed under Table 1 in the “Usage Guidelines” section. The default is informational.

Command Default

Informational

Command Modes

Logging archive configuration

Command History

Release	Modification
Release 3.2	This command was introduced.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

Use the severity command to specify the filter level for syslog messages. All syslog messages higher in severity or the same as the configured value are logged to the archive.

Table 1 describes the acceptable severity levels for the severity argument.

Task ID

Task ID	Operations
logging	read, write

Examples

The following example shows how to specify that warning conditions and higher-severity messages are logged to the archive:

RP/0/0/CPU0:router(config)# logging archive
RP/0/0/CPU0:router(config-logging-arch)# severity warnings

show logging

To display the contents of the logging buffer, use the show logging command in EXEC mode.

show logging [ local location node-id | [ location node-id ] [ start month day hh : mm : ss ] [ process name ] [ string string ] [ end month day hh : mm :ss ] ]

Syntax Description

local location node-id	(Optional) Displays system logging (syslog) messages from the specified local buffer. The node-id argument is entered in the rack/slot/modul e notation.
location node-id	(Optional) Displays syslog messages from the designated node. The node-id argument is entered in the rack/slot/modul e notation.
start month day hh : mm : ss	(Optional) Displays syslog messages with a time stamp equal to or higher than the time stamp specified with the month day mm : hh : ss argument. The ranges for the month day hh : mm : ss arguments are as follows: month—The month of the year. The values for the month argument are: january february march april may june july august september october november december day—Day of the month. Range is 01 to 31. hh :—Hours. Range is 00 to 23. You must insert a colon after the hh argument. mm :—Minutes. Range is 00 to 59. You must insert a colon after the mm argument. ss—Seconds. Range is 00 to 59.
process name	(Optional) Displays syslog messages related to the specified process.
string string	(Optional) Displays syslog messages that contain the specified string.
end month day hh : mm : ss	(Optional) Displays syslog messages with a time stamp equal to or lower than the time stamp specified with the monthday hh : mm : ss argument. The ranges for the month day hh : mm : ss arguments are as follows: month—The month of the year. The values for the month argument are: january february march april may june july august september october november december day—Day of the month. Range is 01 to 31. hh :—Hours. Range is 00 to 23. You must insert a colon after the hh argument. mm :—Minutes. Range is 00 to 59. You must insert a colon after the mm argument. ss—Seconds. Range is 00 to 59.

Command Default

No default behavior or values

Command Modes

EXEC

Command History

Release	Modification
Release 3.2	This command was introduced.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

Use the show logging command to display the state of syslog error and event logging on the processor console. The information from the command includes the types of logging enabled and the size of the buffer.

Task ID

Task ID	Operations
logging	read

Examples

The following is sample output from the show logging command with the process keyword and name argument. Syslog messages related to the init process are displayed in the sample output.

RP/0/0/CPU0:router# show logging process init

Syslog logging: enabled (24 messages dropped, 0 flushes, 0 overruns)
    Console logging: level informational, 59 messages logged
    Monitor logging: level debugging, 0 messages logged
    Trap logging: level informational, 0 messages logged
    Buffer logging: level debugging, 75 messages logged


Log Buffer (16384 bytes):


LC/0/1/CPU0:May 24 22:20:13.043 : init[65540]: %INIT-7-INSTALL_READY : total time 47.522 seconds 
SP/0/1/SP:May 24 22:18:54.925 : init[65541]: %INIT-7-MBI_STARTED : total time 7.159 seconds 
SP/0/1/SP:May 24 22:20:16.737 : init[65541]: %INIT-7-INSTALL_READY : total time 88.984 seconds 
SP/0/SM1/SP:May 24 22:18:40.993 : init[65541]: %INIT-7-MBI_STARTED : total time 7.194 seconds 
SP/0/SM1/SP:May 24 22:20:17.195 : init[65541]: %INIT-7-INSTALL_READY : total time 103.415 seconds 
SP/0/2/SP:May 24 22:18:55.946 : init[65541]: %INIT-7-MBI_STARTED : total time 7.152 seconds 
SP/0/2/SP:May 24 22:20:18.252 : init[65541]: %INIT-7-INSTALL_READY : total time 89.473 seconds 

The following is sample output from the show logging command using both the processname keyword argument pair and location node-id keyword argument pair. Syslog messages related to the “init” process emitted from node 0/1/CPU0 are displayed in the sample output.

RP/0/0/CPU0:router# show logging process init location 0/1/CPU0

Syslog logging: enabled (24 messages dropped, 0 flushes, 0 overruns)
    Console logging: level informational, 59 messages logged
    Monitor logging: level debugging, 0 messages logged
    Trap logging: level informational, 0 messages logged
    Buffer logging: level debugging, 75 messages logged


Log Buffer (16384 bytes):


LC/0/1/CPU0:May 24 22:20:13.043 : init[65540]: %INIT-7-INSTALL_READY : total time 47.522 seconds 

This table describes the significant fields shown in the display.

Table 4 show logging Field Descriptions

Field	Description
Syslog logging	If enabled, system logging messages are sent to a UNIX host that acts as a syslog server; that is, the host captures and saves the messages.
Console logging	If enabled, the level and the number of messages logged to the console are stated; otherwise, this field displays “disabled.”
Monitor logging	If enabled, the minimum level of severity required for a log message to be sent to the monitor terminal (not the console) and the number of messages logged to the monitor terminal are stated; otherwise, this field displays “disabled.”
Trap logging	If enabled, the minimum level of severity required for a log message to be sent to the syslog server and the number of messages logged to the syslog server are stated; otherwise, this field displays “disabled.”
Buffer logging	If enabled, the level and the number of messages logged to the buffer are stated; otherwise, this field displays “disabled.”

Related Commands

Command	Description
clear logging	Clears messages from the logging buffer.

show logging history

To display information about the state of the system logging (syslog) history table, use the show logging history command in EXEC mode.

show logging history

Syntax Description

This command has no arguments or keywords.

Command Default

No default behavior or values

Command Modes

EXEC

Command History

Release	Modification
Release 3.2	This command was introduced.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

Use the show logging history command to display information about the syslog history table, such as the table size, the status of messages, and the text of messages stored in the table. Simple Network Management Protocol (SNMP) configuration parameters and protocol activity also are displayed.

Use the logging history command to change the severity level of syslog messages stored in the history file and sent to the SNMP server.

Use the logging history size to change the number of syslog messages that can be stored in the history table.

Task ID

Task ID	Operations
logging	read

Examples

The following is sample output from the show logging history command:

RP/0/0/CPU0:router# show logging history

Syslog History Table: '1' maximum table entries
saving level 'warnings' or higher
137 messages ignored, 0 dropped, 29 table entries flushed
SNMP notifications disabled

This table describes the significant fields shown in the display.

Table 5 show logging history Field Descriptions

Field	Description
maximum table entries	Number of messages that can be stored in the history table. Set with the logging history size command.
saving level	Level of messages that are stored in the history table and sent to the SNMP server (if SNMP notifications are enabled). Set with the logging history command.
messages ignored	Number of messages not stored in the history table because the severity level is greater than that specified with the logging history command.
SNMP notifications	Status of whether syslog traps of the appropriate level are sent to the SNMP server. Syslog traps are either enabled or disabled through the snmp-server enable command.

Related Commands

Command	Description
logging history	Changes the severity level of syslog messages stored in the history file and sent to the SNMP server.
logging history size	Changes the number of syslog messages that can be stored in the history table.

terminal monitor (logging)

To enable the display of system logging (syslog) messages for the current terminal session, use the terminal monito command in EXEC mode.

terminal monitor [disable]

Syntax Description

disable

(Optional) Disables the display of syslog messages for the current terminal session.

Command Default

No default behavior or values

Command Modes

EXEC

Command History

Release	Modification
Release 3.2	This command was introduced.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes the proper task IDs. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

Use the terminal monitor command to enable the display of syslog messages for the current terminal session.

Note	Syslog messages are not sent to terminal lines unless the logging monitor is enabled.

Use the terminal monitor disable command to disable the display of logging messages for the current terminal session. If the display of logging messages has been disabled, use the terminal monitor command to re-enable the display of logging messages for the current terminal session.

The terminal monitor command is set locally, and does not remain in effect after a terminal session has ended; therefore, you must explicitly enable or disable the terminal monitor command each time that you would like to monitor a terminal session.

Task ID

Task ID	Operations
logging	execute

Examples

The following example shows how to enable the display syslog messages for the current terminal session:

RP/0/0/CPU0:router# terminal monitor

Related Commands

Command	Description
logging monitor	Specifies terminal lines other than console terminal as destinations for syslog messages and limits the number of messages sent to terminal lines based on severity.