In this article I will give an example of setting up logs on Cisco Nexus switches.
Let’s look at the current log settings:
show logging
show logging timestamp
show running-config | include log
show logging internal info
show logging logfile
show logging info
Logging logfile: enabled
Name - messages: Severity - notifications Size - 4194304
show logging console
Logging console: enabled (Severity: critical)
show logging monitor
Logging monitor: enabled (Severity: notifications)
An example of viewing the last 50 entries from the logs:
show logging | last 50
show logging nvram last 50
I personally prefer not to write logs to the device’s memory (disable their recording to the internal memory), but to send them to the syslog server, this way the memory life will be longer and it will be more convenient to view the logs of all devices in one place.
An example of specifying a syslog server:
logging server 192.168.5.5 6 facility local3
logging server 192.168.5.1 6 use-vrf default facility local6
Where, after the IP address, the number 6 is indicated, which determines the logging level, see the full list:
0 – emergency
1 – alert
2 – critical
3 – error
4 – warning
5 – notification
6 – informational
7 – debugging
For example, on devices in the core of the network I indicate 6 – informational, and on access devices that are not so important 4 – warning.
To cancel/delete a command, just write “no” in front of it, for example:
no logging server 192.168.5.1 6 use-vrf default facility local6
Disabling logging to a file:
no logging logfile
An example of setting up logging to the ixnfo.com file with level 4 – warning:
logging logfile ixnfo.com 4 size 4194304
Clearing logs:
clear logging logfile
clear logging nvram
List of available commands in configuration mode:
logging ?
abort Flushes cached data without committing and releases the lock
commit Commits cached data (of all msg types) and releases the lock
console Set console logging
distribute Enables/disables fabric distribution using cfs.
event Interface events
ip IP configuration
level Facility parameter for syslog messages
logfile Set File logging
message Interface events
module Set module(linecard) logging
monitor Set terminal line(monitor) logging level
origin-id Enable origin information for Remote Syslog Server
server Enable forwarding to Remote Syslog Server
source-interface Enable Source-Interface for Remote Syslog Server
timestamp Set logging timestamp granularity
See also my articles:
Debug on Cisco
Installing Rsyslog + Loganalyzer + MySQL
My other articles about Cisco