Description
Field
Text string describing the syslog message.
message-text
Duplicate Message Suppression
Suppressing duplicate messages, especially in a large network, can reduce message clutter and simplify the
task of interpreting the log. The duplicate message suppression feature substantially reduces the number of
duplicate event messages in both the logging history and the syslog file. The suppression and logging process
is the same for logging history and for external syslog servers.
When duplicate message suppression is enabled, two types of events are handled differently:
•
New messages
New messages are always logged immediately.
•
Repeated messages
Repeated messages are subject to suppression. The suppression of repeated messages is interrupted when
a new message occurs.
For information about configuring this feature, see the
Suppressing Duplicate Syslog Messages, on page 302
.
Interruption of Message Suppression
The sequence of suppression intervals is interrupted if a different event occurs. The first occurrence of all
new events is always logged immediately, so a new event aborts the current suppression interval. This clears
the message queue, so another message from the previous sequence is then treated as a new event, and the
suppression sequence starts over.
The repeated message summary is generated only at an interval of 0 , 30, 120 and 600 secs, and not on the
occurrence of a new event. At every interval it is checked if currently any number of messages are suppressed.
If any messages are suppressed at this interval, it's summary is displayed, the message queue is cleared, and
the suppression sequence starts all over. So if a new event occurs before the suppression interval, the message
queues and counters will be cleared, and at the time of interval, there will be no suppression to be summarized.
Here is an example:
RP/0/RSP0/CPU0:router#show running-config logging
Mon Dec
3 12:30:26.346 UTC
logging archive
device harddisk
severity debugging
file-size 4
archive-size 100
!
logging console disable
logging 223.255.254.248
logging 223.255.254.249
logging suppress duplicates
RP/0/RSP0/CPU0:router#
RP/0/RSP0/CPU0:router#
RP/0/RSP0/CPU0:router#
RP/0/RSP0/CPU0:router#
RP/0/RSP0/CPU0:router#run
Cisco ASR 9000 Series Aggregation Services Router System Monitoring Configuration Guide, Release 4.2.x
287
Implementing Logging Services
Duplicate Message Suppression