A requirement for this tool is that a syslog daemon is running on your NAV machine collecting syslog messages from your Cisco gear. Unfortunately the NAV Syslog Analyzer only supports Cisco syslog messages, other messages will be ignored (an improvement is on our road map).
We recommend that you in your syslog configuration log syslog messages from your network equipment to two parallel files, one that is read (and emptied) by NAV and another that is untouched by NAV. The latter can be inspected as usual from shell (you should rotate as you do with other ever-growing log files). The one that NAV reads and empties is configured in the
nav/etc/logger.conf file. It is the NAV background process logengine that does this job. Every minute the log file is checked for new messages. If any, they are removed from the file, parsed and inserted into the NAV logger database.
The NAV logger database takes advantage of the fact that Cisco syslog messages have a predefined structure. Briefly explained a Cisco message type consists of three elements interconnected with hyphen (-). The three elements are:
IP-3-TCP_BADCKSUM IP-4-DUPADDR ISDN-6-CONNECT LINEPROTO-5-UPDOWN LINK-4-ERROR
For any given syslog message, the following are typically found after the syslog server's timestamp:
The NAV logger database models this structure.
Some valid examples are:
May 27 08:32:58 mtfs-sw.ntnu.no 2002 May 27 08:32:53 MET +02:00 %CDP-4-NVLANMISMATCH:Native vlan mismatch detected on port 4/2 Feb 8 12:58:40 18.104.22.168 316371: Feb 8 12:58:39.873 MET: %SEC-6-IPACCESSLOGDP: list 112 permitted icmp 22.214.171.124 -> 126.96.36.199 (0/0), 1 packet Mar 25 10:54:25 somedevice 72: AP:000b.adc0.ffee: *Mar 25 10:15:51.666: %LINK-3-UPDOWN: Interface Dot11Radio0, changed state to up
Incidentally, the log parsing engine has a bug in NAV versions prior to NAV 3.5.3, which cause it to crash if the following format is used (i.e. a year in the originating device's timestamp):
Mar 20 10:27:26 sw_1 607977: Mar 20 2009 10:20:06: %SEC-6-IPACCESSLOGP: list fraVLAN800 denied tcp x.x.x.x(1380) -> y.y.y.y(80), 2 packets
The Syslog Analyzer presents a search form where you can retrieve information of your interest. You may for example see all messages the last 24 hours that are of severity 3, or that has been received from a given switch. In the presented result each message type from a given source box is listed with the number of occurrences seen for this particular message type. By clicking on the number of occurrences further details will be listed.
If there are cases of parsing errors, you can see these (i.e. where the logger process is not able to understand the message).
etc/logger.conf you can define: