38 CHAPTER 3: COLLECTING DATAsingle segment. Traffix Manager uses RMON-2 functionality to build up apicture of communicating devices on the network and the traffic flowingbetween them, including network layer addresses and protocols seen.For further information on RMON-1 and RMON-2, refer to the 3Com®RMON-1 and RMON-2 Backgrounder on the 3Com Web Site:http://www.3com.com/nsc/501305.html.How TraffixManager DiscoversNetwork DevicesUsing RMON-2An agent which supports RMON-2 is able to watch the packets on thenetwork segment to which it is attached. Depending on the protocol inuse, most packets typically contain a source and destination address. TheRMON-2 agent decodes this address information and uses it to buildtables of data about the communicating devices and the traffic flowingbetween them, including network layer addresses and protocols seen.This information is then retrieved by Traffix Manager and is used to builda graphical topology of your network (the Traffix Manager Map) and tocompile a list of active devices on your network.As a result of the RMON-2 method of discovering devices, you may seemore than one object corresponding to the same physical device. Forexample, separate entries for a device may be made under its ARP, IP andIPX addresses. For the same reason, “non-device” objects, such as IPbroadcast and multicast addresses, will appear in the Map.With no RMON-2 conversation data collected, Traffix Manager is able toperform only limited functions.If an agent selected for data collection supports RMON-1 only, TraffixManager is only able to collect line statistics data from that agent andperform basic agent maintenance operations. See Appendix I, “UsingRMON-1 Agents” for more information.
