OP5 Monitor supports both agent-less and agent-based remote monitoring.

Agent-less monitoring approaches

  • 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.

Agent Environment
NSClient Microsoft Windows
Net-Snmpd (SNMP) Unix & Linux
NRPE Unix & Linux
Windows Syslog Agent Microsoft Windows
  NSClient++ SNMPv3 (net-snmpd) NRPE Agent SSH WMI
Linux Partly Yes Yes Yes No
Windows Yes No [2] No No Yes
Network equipment No Yes No No No
Can run standard monitoring plugins No Yes Yes Yes No
Authentication of client IP address User/pass IP address Public/private key User/pass
Encryption Good Good Bad Good Good
Performance Good Good Good Good [1] Low
Central threshold management Yes Yes [4] No [3] Yes Yes
Local threshold management Yes No Yes Yes No
Custom plugin/command possibility Yes Yes Yes Yes Yes

[1] Very fast using SSH multiplexing

[2] SNMP on Windows is deprecated and not recommended by Microsoft

[3] Thresholds can be managed centrally, but only insecurely

[4] Using 'pass_persist'