RMON: Remote Monitoring MIBs (RMON1 and RMON2)
Remote Monitoring (RMON) is a standard monitoring specification that enables various
network monitors and console systems to exchange network-monitoring data. RMON provides network administrators with more freedom
in selecting network-monitoring probes and consoles with features that meet their particular networking needs.
RMON was originally developed to address the problem of managing LAN segments
and remote sites from a central location. The RMON specification, which is an extension of the SNMP MIB, is a standard monitoring
specification. Within an RMON network monitoring data is defined by a set of statistics and functions and exchanged between
various different monitors and console systems. Resultant data is used to monitor network utilization for network planning
and performance-tuning, as well as assisting in network fault diagnosis.
There are 2 versions of RMON: RMON1 (RMONv1)and RMON2 (RMONv2). RMON1 defined
10 MIB groups for basic network monitoring, which can now be found on most modern network hardware. RMON2 (RMONv2) is an extension
of RMON that focuses on higher layers of traffic above the medium access-control (MAC) layer. RMON2 has an emphasis on IP
traffic and application-level traffic. RMON2 allows network management applications to monitor packets on all network
layers. This is difference from RMON which only allows network monitoring at MAC layer or below.
RMON solutions are comprised of two components: a probe (or an agent or a monitor),
and a client, usually a management station. Agents store network information within their RMON MIB and are normally found
as embedded software on network hardware such as routers and switches although they can be a program running on a PC. Agents
can only see the traffic that flows through them so they must be placed on each LAN segment or WAN link that is to be monitored.
Clients, or management stations, communicate with the RMON agent or probe, using SNMP to obtain and correlate RMON data.
Now, there are a number of variations to the RMON MIB. For example, the Token
Ring RMON MIB provides objects specific to managing Token Ring networks. The SMON MIB extends RMON by providing RMON analysis
for switched networks.