- WMI - for Windows servers
- check_ssh - using SSH for Linux servers
- SNMPv3 - XEN and KVM servers, as well as SNMP-capable networking equipment. Please refer to check_snmp.
OP5 recommends the following agent-based monitoring:
SNMPv3 offers secure authentication and encryption, and is very easy to configure. The net-snmpd SNMP agent is available in the default package repository for most Linux and UNIX-based operating systems. SNMPv3 also supports running existing NRPE plugins. Instructions on how to configure SNMP-based remote monitoring are available here.
NRPE had been the most popular agent for monitoring Linux servers. However, SNMPv3 provides far better security and ease of configuration. SNMPv3 can control a user via authentication and restrict that user to read-only activity, which makes monitoring less risky in secured environments. Nevertheless, NRPE is still available for organizations that have standardized their monitoring on it.
|Net-Snmpd (SNMP)||Unix & Linux|
|NRPE||Unix & Linux|
|Windows Syslog Agent||Microsoft Windows|
|NSClient++||SNMPv3 (net-snmpd)||NRPE Agent||SSH||WMI|
|Can run standard monitoring plugins||No||Yes||Yes||Yes||No|
|Authentication of client||IP address||User/pass||IP address||Public/private key||User/pass|
|Central threshold management||Yes||Yes ||No ||Yes||Yes|
|Local threshold management||Yes||No||Yes||Yes||No|
|Custom plugin/command possibility||Yes||Yes||Yes||Yes||Yes|
 Very fast using SSH multiplexing
 SNMP on Windows is deprecated and not recommended by Microsoft
 Thresholds can be managed centrally, but only insecurely
 Using 'pass_persist'