Handbook of Local Area Networks, 1998 Edition:LAN Management Click Here! Search the site:   ITLibrary ITKnowledge EXPERT SEARCH Programming Languages Databases Security Web Services Network Services Middleware Components Operating Systems User Interfaces Groupware & Collaboration Content Management Productivity Applications Hardware Fun & Games EarthWeb sites Crossnodes Datamation Developer.com DICE EarthWeb.com EarthWeb Direct ERP Hub Gamelan GoCertify.com HTMLGoodies Intranet Journal IT Knowledge IT Library JavaGoodies JARS JavaScripts.com open source IT RoadCoders Y2K Info Previous Table of Contents Next Benefits of RMON2 The directory system group, rather than RMON’s filter, allows information to be viewed by protocols in a logical hierarchical parsing approach rather than a flat, logical, filter paradigm. RMON2 operates at the network layer, which allows it, unlike the original RMON, to look across routers and capture intersegment traffic. Although network probes are decreasing in cost, the budget-conscious manager cannot afford to install probes on each segment. With RMON2 and its networking-aware capabilities, the network manager can deploy probes more judiciously and allow the more powerful software to capture data from more than one segment. RMON2 provides time filtering and enhanced TopN, which minimizes overhead. By accessing only the data that has changed since the last poll, time filtering allows incremental data retrieval from the probes. RMON2 allows end-to-end conversations and provides building blocks for extending service level management to applications. It allows interoperable, seven-layer protocol decodes. This is critical for end users that track application response times—not how well a router is passing packets. It provides an architecture for integrating network and system response time (such as HP’s Internetwork Response Time and HP’s MeasureWare Agent) to provide data base and applications response time end-to-end and delineate the system and network-specific elements of the latency. RMON2 and the Web With the hype about internets and intranets, managers are being asked to provide efficient access over expensive WAN links to global Web sites. Although RMON was developed for the LAN, many managers are using RMON packages with WAN extensions that check carrier-related link statistics to provide reporting information about Web access. What network managers often discover is that links are not necessarily being used for corporate objectives. The Web is also being used by RMON vendors to provide heterogeneous platform access to performance reports and statistics. Macintosh, Windows, and OS/2 users can access the information in a familiar operating environment rather than having to learn new operating system. RMON and Virtual LANs A virtual LAN is a high-speed, low-latency broadcast group that unites an arbitrary collection of end stations on multiple LAN segments connected through layers 1, 2, or 3. RMON was developed to look at physical network segments — not logical segments. To develop statistics on multiple virtual LANs, Lannet (now part of Madge Networks) developed a switched RMON implementation. It allows network administrators to look at statistics across multiple virtual segments, and if a segment has a problem, then the RMON statistics features can look for more granular information. Unfortunately, these solutions are expensive, and they still require an administrator that can switch the RMON microscope at the appropriate time to the segment experiencing problems. If virtual LANs become popular in corporate America, end users will need to plan a strategy of standalone and switched RMON to provide a cost-effective and flexible method of managing the new environment. Managers should query their internetworking vendor as to which groups of RMON are supported on the particular switch. For example, Cisco has stated that it will not provide integrated RMON on any of their high-end 7000 series routers because the overhead decreases packet throughput at the port level. SUMMARY In the distributed computing arena, the cost of supporting enterprise computing has risen greatly. It is difficult to maintain systems and network administrators at a central site, and it is impossible to cost-effectively locate or constantly dispatch resources to smaller remote sites. RMON allows inexpensive hardware probes and software to be located at remote sites and report back information on an exception basis. That data can then be dissected and analyzed by trained LAN administrators. Even at central sites, the mushrooming of LANs has strained network and systems administrators. It is not possible to locate full-time administrators at every LAN segment, and the passive polling of SNMP is not adequate to gauge the health of these segments. RMON thus provides a means by which network administrators can manage more LANs with the help of fewer people (see Exhibit 7-1-6). Exhibit 7-1-6.  How RMON Saves Money Previous Table of Contents Next Use of this site is subject certain Terms & Conditions. Copyright (c) 1996-1999 EarthWeb, Inc.. All rights reserved. Reproduction in whole or in part in any form or medium without express written permission of EarthWeb is prohibited. Please read our privacy policy for details.