1. RMON 1

2. RMON is a set of standardized MIB variables that monitor networks. Even if RMON initially referred to only the RMON MIB, the term RMON now is often used to refer to the concept of remote monitoring and to the entire series of RMON MIB extensions 2

3. RMON Goal The initial goal of RMON was to:  monitor network traffic in a local-area network (LAN) environment  to provide comprehensive information for network fault diagnosis, planning, and performance tuning to network administrators. 3

4. RMON approach RMON implements a passive collection approach that measures specific aspects of the traffic without interfering by adding monitoring traffic. 4

5. RMON devices RMON can be implemented in network elements, such as Cisco routers and switches, or it can be deployed using dedicated RMON probes 5

6. RMON Probe Data gatherer - a physical device Data analyzer Processor that analyzes data 6

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8. Note that RMON is embedded monitoring remote FDDI LAN Analysis done in NMS 8

9. RMON Benefits Monitors and analyzes locally and relays data; Less load on the network Needs no direct visibility by NMS; More reliable information Permits monitoring on a more frequent basis and hence faster fault diagnosis Increases productivity for administrators 9

10. RMON 1 limitation Although RMON became successful, implementations made it clear that monitoring on OSI Layer 2 was limited when monitoring wide-area network (WAN) traffic (OSI Layer 3 and above) 10

11. RMON 2 RMON version 2 (RMON 2) is an extension to RMON version 1 (RMON 1), which refers to the initial RMON specifications monitoring on OSI Layer 2. RMON 2 focuses on the layers of traffic above the Media Access Control (MAC) layer; the main enhancement of RMON 2 is the capability to measure Layer 3 network traffic and application statistics. 11

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14. 14 RMON groups start with identifier 1.3.6.1.2.1.16

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16. RMON1: Ethernet RMON groups (rmon 1 - rmon 9) RMON1: Extension: Token ring extension (rmon 10) RMON2: Higher layers (3-7) groups (rmon 11 - rmon 20) 16

17. RMON 1 17 Group number Group name 1rmon 1Statistics 2rmon 2History 3rmon 3Alarms 4rmon 4Hosts 5rmon 5HostTopN 6rmon 6Traffic Matrix 7rmon 7Filters 8rmon 8Packet Capture 9rmon 9Events 10rmon 10Token Ring

18. RMON 1 Ten groups divided into three categories Statistics groups (rmon 1, 2, 4, 5, 6, and 10)) Event reporting groups (rmon 3 and 9) Filter and packet capture groups(romon 7 and 8) 18

19. 19 Group nameSuper group Statistics Statistics groups History Hosts HostTopN Traffic Matrix Token Ring Alarms Event reporting groups Events Filters Filter and packet capture groups Packet Capture

20. RMON 1 Statistics groups RMON 1 Group FunctionElements StatisticsContains statistics measured by the RMON probe for each monitored interface on this device. (objects ) Packets dropped, packets sent, bytes sent (octets), broadcast packets, multicast packets, CRC errors, runts, giants, fragments, jabbers, collisions, and counters for packets ranging from 64 to 128, 128 to 256, 256 to 512, 512 to 1024, and 1024 to 1518 bytes. History Records periodic statistical samples from a network and stores them for later retrieval. Sample period, number of samples, items sampled 20

21. RMON 1 Statistics groups RMON 1 Group FunctionElements HostsContains statistics associated with each host discovered on the LAN. Host MAC address, packets, and bytes received and transmitted, as well as number of broadcast, multicast, and error packets. HostTopNPrepares tables that describe the hosts that top a list ordered by one of their base statistics over an interval specified by the management station. Thus, these statistics are rate-based Statistics, host(s), sample start and stop periods, rate base, and duration. 21

22. RMON 1 Statistics groups RMON 1 Group FunctionElements Traffic Matrix Stores statistics for conversations between sets of two MAC addresses. As the device detects a new conversation, it creates a new entry in its table. Source and destination MAC address pairs and packets, bytes, and errors for each conversation. Token Ring Provides additional statistics for Token Ring networks. Ring Provides additional statistics for Token Ring networks. MAC layer statistics, promiscuous statistics, MAC layer history, promiscuous history, ring station order table, alarms, events. 22

23. RMON 1 Event reporting groups RMON 1 Group FunctionElements AlarmsPeriodically takes statistical samples from variables in the probe and compares them with previously configured thresholds. If the monitored variable crosses a threshold, an event is generated. Includes the alarm table: alarm type, interval, starting threshold, stop threshold.Note: The Alarms group requires the implementation of the Events group. EventsControls the generation and notification of events from this device. Event type, description, the last time the event was sent. 23

24. RMON 1 Filter and packet capture groups RMON 1 Group FunctionElements FiltersEnables packets to be matched by a filter equation. These matched packets form a data stream that might be captured or that might generate events Bit-filter type (mask or not mask), filter expression (bit level), conditional expression (and, or, not) to other filters. Packet Capture Enables packets to be capturedSize of buffer for captured packets, full status (alarm), and number of captured packets. 24

25. RMON 1 Tables 25

26. RMON summery The principles of RMON are as follows: It is a set of standardized MIB variables monitoring networks. It offers information that lets administrators analyze network utilization, including data and error statistics. RMON 1 includes only data link layer (Layer 2) details. RMON 2 offers network layer to application layer details (Layer 3 and up). Collection data is accessible via SNMP. The MIB objects are intended as an interface between a network agent and a management application; they are not intended for direct manipulation by humans. These functions should be handled by the network management application. 26

27. 27 Runts In networks, a runt is a packet that is too small. For example, the Ethernet protocol requires that each packet be at least 64 bytes long. In Ethernet, which operates on the idea that two parties can attempt to get use of the line at the same time and sometimes do, runts are usually the fragments of packet collisions. Runts can also be the result of bad wiring or electrical interference. Runts are recorded by programs that use the Remote Network Monitoring (RNM) standard information base for network adminstration. RMON calls them "undersize packets".packetEthernetRMON