Cricket and SNMP

Using Cricket to manage SNMP objects

Systems and Network Management

SNMP 2

Cricket: what is it• Can monitor almost anything in a computer

network• Can use SNMP, scripts, WMI on Windows,

programs, files,… as sources of data• Can also send traps, or set alarms• Keeps data in fixed sized “round-robin database”• Data kept over last day, week, month, year• Data visible in graphs through a web interface• Very useful in detecting trends, knowing when

something is wrong, or “different from usual”• Graphs very easy to understand• Can be installed on Linux, Unix, Windows.

Systems and Network Management

SNMP 3

Documentation for Cricket• Cricket documentation (plenty!) is at

http://cricket.sourceforge.net/support/doc/

• Today we look at:• http://cricket.sourceforge.net/support/doc/neta

-paper/paper.html• http://cricket.sourceforge.net/support/doc/intro

.html• http://cricket.sourceforge.net/support/doc/new-

devices.html

• Good, helpful, active mailing list

Systems and Network Management

SNMP 4

When should I use Cricket?

• Great if your boss expects you to monitor the company network, but no budget for huge NMS

• Great if you also have a huge NMS and big budget– The graphs are easy to set up– the view over the long and short term

is better than what many big NMS systems provide

Systems and Network Management

SNMP 5

Cricket’s “Config Tree”• Many programs have a single

configuration file, or one directory with some configuration files

• Cricket has a directory tree of configuration files

• Called a Config Tree• As we set up in the lab:

– ~cricket/cricket-config

• Each directory in cricket-config contains a file called Defaults

Systems and Network Management

SNMP 6

Config Tree• Defaults file holds settings for all directories

below– Unless they override these settings with their own

settings in another file.

• When Cricket processes a directory,– Processes Defaults file first (if present)– Processes all other ordinary files next’– Finally processes each of subdirectories

• Other files apply changes to current directory settings only

• Defaults file applies to all subdirectories too

Systems and Network Management

SNMP 7

Tags and values

• Look at the Top level Defaults fileve you (at ictlab:/var/ftp/snmp/servers)

• You will see:• snmp-community = public• snmp-port = 161• snmp = %snmp-community%@%snmp-host%:

%snmp-port%:%snmp-timeout%:%snmp-retries%:%snmp-backoff%:%snmp-version%

Systems and Network Management

SNMP 8

Tags and values 2

• Look at the servers files that I gave you (at ictlab:/var/ftp/snmp/servers)

• You will see:• server = %auto-target-name%• snmp-host = %server%