Monitoring on iniy.org

nagios nsca wrapper

Tue, 30 Nov 2010 21:56:29 +0000

nsca vs. nrpe

Personally i favor nrpe as I can control at a central point which checks are really run. I can have 30 checks in the config but, use only 5 of them. With nsca you have to adjust the cronjob-list on every server and have no central option.

nagios checks too slow

Tue, 30 Nov 2010 21:51:12 +0000

lately i came across a really dumb problem. Our nagios server sucked like hell and I couldn’t find the source of the problem. I was tuning nagios-parameters but nothing changed. The server had low load and cpu-usage, but the checks were delayed about 15-30 minutes (should be checked every 2 minutes). Then I found the solution. nagios active hostchecks YOU HAVE TO DISABLE THIS CRAP. In Nagios 2.x the hostchecks are serial, thus delaying all other checks, while checking. With some hundreds hosts it can happen fast, that the server is almost only checking the hosts and not doing anything else.

Mini-Howto: SNMP (Simple Network Management Protocol)

Thu, 21 Jan 2010 12:33:06 +0000

This Howto covers some SNMP Basics and examples how you can read some values

Introduction

The “Simple Network Management Protocol” is a powerful possibility to query network-devices for information, or even to manage them. It’s often also a security risk. As SNMP is a bit difficult to use at the beginning some administrators just skip over it. This can lead to security holes, when SNMP is activated by default on devices. For example on some HP-Switches I configured the default setting for SNMP was set to “read + write” for “public”. SNMP was limited to the local network, but still this enables all connected servers to shutdown ports and have other fun as they wanted. Often the configuration is like that to enable some configuration tools to control the switches.