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This chapter describes how to configure system message logging on the Cisco Nexus 5000 Series switch and contains the following sections:
You can use system message logging to control the destination and to filter the severity level of messages that system processes generate. You can configure logging to terminal sessions, a log file, and syslog servers on remote systems.
By default, the Cisco Nexus 5000 Series switch outputs messages to terminal sessions.
By default, the switch logs system messages to a log file.
The following table describes the severity levels used in system messages. When you configure the severity level, the system outputs messages at that level and lower.
Level |
Description |
---|---|
0 – emergency |
System unusable |
1 – alert |
Immediate action needed |
2 – critical |
Critical condition |
3 – error |
Error condition |
4 – warning |
Warning condition |
5 – notification |
Normal but significant condition |
6 – informational |
Informational message only |
7 – debugging |
Appears during debugging only |
The switch logs the most recent 100 messages of severity 0, 1, or 2 to the NVRAM log. You cannot configure logging to the NVRAM.
You can configure which system messages should be logged based on the facility that generated the message and its severity level.
syslog servers run on remote systems that are configured to log system messages based on the syslog protocol. You can configure the Cisco Nexus 5000 Series to sends its logs to up to three syslog servers.
To support the same configuration of syslog servers on all switches in a fabric, you can use the Cisco Fabric Services (CFS) to distribute the syslog server configuration.
Note |
When the switch first initializes, messages are sent to syslog servers only after the network is initialized. |
Configuring System Message Logging
You can configure the switch to log messages by their severity level to console, Telnet, and SSH sessions.
By default, logging is enabled for terminal sessions.
3.
switch(config)# logging console [severity-level]
4.
(Optional) switch(config)# no logging console [severity-level]
5.
switch(config)# logging monitor [severity-level]
6.
(Optional) switch(config)# no logging monitor [severity-level]
7.
(Optional) switch# show logging console
8.
(Optional) switch# show logging monitor
9.
(Optional) switch# copy running-config startup-config
The following example shows how to configure a logging level of 3 for the console:
switch# configure terminal
switch(config)# logging console 3
The following example shows how to display the console logging configuration:
switch# show logging console
Logging console: enabled (Severity: error)
The following example shows how to disable logging for the console:
switch# configure terminal
switch(config)# no logging console
The following example shows how to configure a logging level of 4 for the terminal session:
switch# terminal monitor
switch# configure terminal
switch(config)# logging monitor 4
The following example shows how to display the terminal session logging configuration:
switch# show logging monitor
Logging monitor: enabled (Severity: warning)
The following example shows how to disable logging for the terminal session:
switch# configure terminal
switch(config)# no logging monitor
You can configure the switch to log system messages to a file. By default, system messages are logged to the file log:messages.
2.
switch(config)# logging logfile logfile-name severity-level [size bytes]
3.
(Optional) switch(config)# no logging logfile [logfile-name severity-level [size bytes]]
4.
(Optional) switch# show logging info
5.
(Optional) switch# copy running-config startup-config
The following example shows how to configure a switch to log system messages to a file:
switch# configure terminal
switch(config)# logging logfile my_log 6 size 4194304
The following example shows how to display the logging configuration (some of the output has been removed for brevity):
switch# show logging info
Logging console: enabled (Severity: debugging)
Logging monitor: enabled (Severity: debugging)
Logging linecard: enabled (Severity: notifications)
Logging fex: enabled (Severity: notifications)
Logging timestamp: Seconds
Logging server: disabled
Logging logfile: enabled
Name - my_log: Severity - informational Size - 4194304
Facility Default Severity Current Session Severity
-------- ---------------- ------------------------
aaa 3 3
aclmgr 3 3
afm 3 3
altos 3 3
auth 0 0
authpriv 3 3
bootvar 5 5
callhome 2 2
capability 2 2
cdp 2 2
cert_enroll 2 2
...
You can configure the severity level and time-stamp units of messages logged by modules and facilities.
2.
switch(config)# logging module [severity-level]
3.
switch(config)# logging level facility severity-level
4.
(Optional) switch(config)# no logging module [severity-level]
5.
(Optional) switch(config)# no logging level [facility severity-level]
6.
(Optional) switch# show logging module
7.
(Optional) switch# show logging level [facility]
8.
(Optional) switch# copy running-config startup-config
The following example shows how to configure the severity level of module and specific facility messages:
switch# configure terminal
switch(config)# logging module 3
switch(config)# logging level aaa 2
You can configure the time-stamp units of messages logged by the Cisco Nexus 5000 Series switch.
2.
switch(config)# logging timestamp {microseconds | milliseconds | seconds}
3.
(Optional) switch(config)# no logging timestamp {microseconds | milliseconds | seconds}
4.
(Optional) switch# show logging timestamp
5.
(Optional) switch# copy running-config startup-config
Command or Action | Purpose | |
---|---|---|
Step 1 | switch# configure terminal |
Enters configuration mode. |
Step 2 | switch(config)# logging timestamp {microseconds | milliseconds | seconds} |
Sets the logging time-stamp units. By default, the units are seconds. |
Step 3 | switch(config)# no logging timestamp {microseconds | milliseconds | seconds} |
(Optional) Resets the logging time-stamp units to the default of seconds. |
Step 4 | switch# show logging timestamp |
(Optional) Displays the logging time-stamp units configured. |
Step 5 | switch# copy running-config startup-config |
(Optional) Copies the running configuration to the startup configuration. |
The following example shows how to configure the time-stamp units of messages:
switch# configure terminal
switch(config)# logging timestamp milliseconds
switch(config)# exit
switch# show logging timestamp
Logging timestamp: Milliseconds
You can configure up to three syslog servers that reference remote systems where you want to log system messages.
2.
switch(config)# logging server host [severity-level [use-vrf vrf-name [facility facility]]]
3.
(Optional) switch(config)# no logging server host
4.
(Optional) switch# show logging server
5.
(Optional) switch# copy running-config startup-config
Command or Action | Purpose | |||
---|---|---|---|---|
Step 1 | switch# configure terminal |
Enters configuration mode. |
||
Step 2 | switch(config)# logging server host [severity-level [use-vrf vrf-name [facility facility]]] |
|
||
Step 3 | switch(config)# no logging server host |
(Optional) Removes the logging server for the specified host. |
||
Step 4 | switch# show logging server |
(Optional) Displays the syslog server configuration. |
||
Step 5 | switch# copy running-config startup-config |
(Optional) Copies the running configuration to the startup configuration. |
The following examples show how to configure a syslog server:
switch# configure terminal
switch(config)# logging server 172.28.254.254 5 use-vrf default facility local3
switch# configure terminal
switch(config)# logging server 172.28.254.254 5 use-vrf mgmt0 facility local3
Command | Descriptions |
---|---|
show logging server | Displays the configured syslog servers. |
You can configure a syslog server on a UNIX or Linux system by adding the following line to the /etc/syslog.conf file:
facility.level <five tab characters> action
The following table describes the syslog fields that you can configure.
Field |
Description |
||
---|---|---|---|
Facility |
Creator of the message, which can be auth, authpriv, cron, daemon, kern, lpr, mail, mark, news, syslog, user, local0 through local7, or an asterisk (*) for all. These facility designators allow you to control the destination of messages based on their origin.
|
||
Level |
Minimum severity level at which messages are logged, which can be debug, info, notice, warning, err, crit, alert, emerg, or an asterisk (*) for all. You can use none to disable a facility. |
||
Action |
Destination for messages, which can be a filename, a host name preceded by the at sign (@), or a comma-separated list of users or an asterisk (*) for all logged-in users. |
1. Log debug messages with the local7 facility in the file /var/log/myfile.log by adding the following line to the /etc/syslog.conf file:
2. Create the log file by entering these commands at the shell prompt:
3. Make sure the system message logging daemon reads the new changes by checking myfile.log after entering this command:
You can distribute the syslog server configuration to other switches in the network by using the Cisco Fabric Services (CFS) infrastructure.
After you enable syslog server configuration distribution, you can modify the syslog server configuration and view the pending changes before committing the configuration for distribution. As long as distribution is enabled, the switch maintains pending changes to the syslog server configuration.
Note |
If the switch is restarted, the syslog server configuration changes that are kept in volatile memory may be lost. |
You must have configured one or more syslog servers.
2.
switch(config)# logging distribute
3.
switch(config)# logging commit
4.
switch(config)# logging abort
5.
(Optional) switch(config)# no logging distribute
6.
(Optional) switch# show logging pending
7.
(Optional) switch# show logging pending-diff
8.
(Optional) switch# show logging internal info
9.
(Optional) switch# copy running-config startup-config
Command or Action | Purpose | |
---|---|---|
Step 1 | switch# configure terminal |
Enters configuration mode. |
Step 2 | switch(config)# logging distribute |
Enables distribution of syslog server configuration to network switches using the CFS infrastructure. By default, distribution is disabled. |
Step 3 | switch(config)# logging commit |
Commits the pending changes to the syslog server configuration for distribution to the switches in the fabric. |
Step 4 | switch(config)# logging abort |
Cancels the pending changes to the syslog server configuration. |
Step 5 | switch(config)# no logging distribute |
(Optional) Disables distribution of syslog server configuration to network switches using the CFS infrastructure. You cannot disable distribution when configuration changes are pending. See the logging commit and logging abort commands. By default, distribution is disabled. |
Step 6 | switch# show logging pending |
(Optional) Displays the pending changes to the syslog server configuration. |
Step 7 | switch# show logging pending-diff |
(Optional) Displays the differences from the current syslog server configuration to the pending changes of the syslog server configuration. |
Step 8 | switch# show logging internal info |
(Optional) Displays information about the current state of syslog server distribution and the last action taken. |
Step 9 | switch# copy running-config startup-config |
(Optional) Copies the running configuration to the startup configuration. |
You can display or clear messages in the log file and the NVRAM.
1.
switch# show logging last number-lines
2.
switch# show logging logfile [start-time yyyy mmm dd hh:mm:ss] [end-time yyyy mmm dd hh:mm:ss]
3.
switch# show logging nvram [last number-lines]
4.
switch# clear logging logfile
5.
switch# clear logging nvram
Command or Action | Purpose | |
---|---|---|
Step 1 | switch# show logging last number-lines |
Displays the last number of lines in the logging file. You can specify from 1 to 9999 for the last number of lines. |
Step 2 | switch# show logging logfile [start-time yyyy mmm dd hh:mm:ss] [end-time yyyy mmm dd hh:mm:ss] |
Displays the messages in the log file that have a time stamp within the span entered. If you do not enter an end time, the current time is used. You enter three characters for the month time field, and digits for the year and day time fields. |
Step 3 | switch# show logging nvram [last number-lines] |
Displays the messages in the NVRAM. To limit the number of lines displayed, you can enter the last number of lines to display. You can specify from 1 to 100 for the last number of lines. |
Step 4 | switch# clear logging logfile |
Clears the contents of the log file. |
Step 5 | switch# clear logging nvram |
Clears the logged messages in NVRAM. |
The following example shows how to display messages in a log file:
switch# show logging last 40
switch# show logging logfile start-time 2007 nov 1 15:10:0
switch# show logging nvram last 10
The following example shows how to clear messages in a log file:
switch# clear logging logfile
switch# clear logging nvram
To display system message logging configuration information, perform one of the following tasks:
Command |
Purpose |
---|---|
switch# show logging console | Displays the console logging configuration. |
switch# show logging info | Displays the logging configuration. |
switch# show logging internal info | Displays the syslog distribution information. |
switch# show logging last number-lines | Displays the last number of lines of the log file. |
switch# show logging level [facility] | Displays the facility logging severity level configuration. |
switch# show logging logfile [start-time yyyy mmm dd hh:mm:ss] [end-time yyyy mmm dd hh:mm:ss] | Displays the messages in the log file. |
switch# show logging module | Displays the module logging configuration. |
switch# show logging monitor | Displays the monitor logging configuration. |
switch# show logging nvram [last number-lines] | Displays the messages in the NVRAM log. |
switch# show logging pending | Displays the syslog server pending distribution configuration. |
switch# show logging pending-diff | Displays the syslog server pending distribution configuration differences. |
switch# show logging server | Displays the syslog server configuration. |
switch# show logging session | Displays the logging session status. |
switch# show logging status | Displays the logging status. |
switch# show logging timestamp | Displays the logging time-stamp units configuration. |
The following table lists the default settings for system message logging parameters.
Parameters |
Default |
---|---|
Console logging |
Enabled at severity level 2 |
Monitor logging |
Enabled at severity level 2 |
Log file logging |
Enabled to log:messages at severity level 5 |
Module logging |
Enabled at severity level 5 |
Facility logging |
Enabled; |
Time-stamp units |
Seconds |
syslog server logging |
Disabled |
syslog server configuration distribution |
Disabled |