Automation

SNMPv3 Informs

In a recent monitoring project we had to set up SNMPv3 informs form the servers in the data center to our monitoring system. Since I found no really convincing documentation in the net I decided to write something here how to receive SNMPv3 in the trapd and how to send informs from the disman part of the net-snmp agent.

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Real Time Performance Monitoring

Every administrator should know the performance of the servers and services he is responsible for. Normally the performance of services if measured in actions per time. For instance for a database this would be accesses or inserts per second, for a webserver sites delivered per second. For a mailserver this figure are messages handled per second.

Of course every admin can estimate the performance of his servers. But measuring is always better the guessing. Measuring things on productive live systems is the task of a monitoring systems.

In this article I want to present a method to measure the performance of live systems in real time. This results in much more accurate values than any educated guess. I will demonstrate my method with a mail server, but the method can be applied to any service. You just have to measure the throughtput and CPU usage and combine both values with some simple math.

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SNMP Proxy

A very little known feature of SNMP is the proxy. You can configure a good SNMP agent to proxy requests to an other SNMP entity. In this article I want do cast some light on this feature. I used it the request performance data form a switch that speaks only IPv4 while the transport network between the management station and the agents is IPv6.

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PGP-Schlüssel einfach und sicher verteilen

Die PGP-Schlüsselserver waren eine "ad-hoc" Lösung der PGP-Benutzer der ersten Stunde. Das Verfahren ist kompliziert und bietet unnötig Angriffsfläche. OPENPGPKEYS, ein RFC kurz vor der Verabschiedung, hat das Zeug diesen Anachronismus durch ein einfaches uns sicheres Verteilverfahren zu ersetzen. In meinem Post gehe ich auf die Vor- und Nachteile ein und zeige wie wir bei sys4 OPENPGPKEYS nutzen.

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