Network Uptime

==== Starting Delimiter "It's a Released Beta" ====

I'm going to use this month's Starting Delimiter to climb on my soapbox and do something unusual - complain about something. This action nearly violates two of my standards for the newsletter; don't complain, and don't bash people. I'll attempt to justify myself by pointing out that this isn't a bashing session, just an observation of the industry's direction. Since I used to _be_ a vendor (send your letters of condolence to the address listed below), I also feel that I have a point of reference.

Marketing has taken over our industry. I know this isn't a revelation, but I've recently noticed that vendors are taking more liberties with reality (did I say that?). If something isn't shipping, then don't quote that part number and price in a proposal. If you must quote a piece of vaporware, then clearly document the status of the product and the expected ship date.

I've seen proposals valued close to one million dollars (do the Dr. Evil move with the pinky) that quoted hardware that didn't exist. After innocently finding out about the vaporware through some casual conversations and Q&A with the vendor, they stated that the product is "a released beta", and therefore can be quoted since the plans are to have the product available by the time I purchase. *bzzzz* Wrong answer. It either exists, or it doesn't.

We need to be more careful with our technology decisions, especially since these decisions and the products we purchase are becoming more difficult to understand and integrate into our environments. It may take a few more hours to dive into the vendor's product quote, but we'll sleep well knowing that we made an educated purchase.

Have you ever been involved in a confusing or frustrating situation with a vendor? Email me with your story, and I'll anonymously broadcast your venting in an upcoming edition of Network Uptime.

Your email messages keep arriving, and we're grateful. Your support of our newsletter has been extremely encouraging, and we appreciate your comments. Your messages help to increase the quality of the newsletter and the web page. THANK YOU!

James Messer
Editor, Network Uptime
James@NetworkUptime.com

==== - Uptime Update - Protocol Analysis on a Switched Network Part 2 - Using a Hub to View a Switched Network ====

In the last issue, we detailed four different methods of connecting a protocol analyzer or monitoring tool to a switched network. We identified LAN hubs, network taps, 'mirror' ports, and matrix switches, and we provided an overview of each methodology. This issue will discuss the advantages and disadvantages of using LAN hubs for analyzer connectivity.

Although using a LAN hub to connect a protocol analyzer is limited to half- duplex LANs, and is one of the easiest and most effective ways to connect a monitoring tool to a switched network connection.

The most common use for a LAN hub is in an Ethernet environment. Most computer stores and networking catalogs have low-cost 10/100 Ethernet hubs for less than $50. Remember that you need to purchase a HUB, and not a SWITCH. It's this shared environment that provides visibility to the network analysis tools.

Almost any hub will work, and most engineers will choose a small hub with about four ports and a small power supply or 'cube.' For the analysts that travel, keep in mind that the power supply can be larger than the hub itself! You may need to look at many hub models until you find one that works best for your environment.

The hub doesn't require any special network management or configuration utilities. Don't worry that the hub won't provide SNMP management or auto-partitioning. This is a piece of hardware that will be used for a very specialized application, and additional bells-and-whistles aren't necessary.

Before using the hub, additional cables may be required to provide connectivity between the switch, the hub, and the network device. Some switches use Ethernet cross-over cables to provide end-station connectivity, and these cables won't work with a hub.

The integration of the hub between the LAN switch and the end-station requires disconnection of the current link, and the installation of the hub into the middle of the connection. In most cases this only takes a few seconds, but you should always be wary of disconnecting production equipment from the production network during working hours. If possible, install the hub during a maintenance downtime for later use.

Once the hub is in place, a network analysis tool can be connected to the hub to view communications between the LAN switch and the end-station. Since the analyzer doesn't communicate on the network, the hub is simply a passive 'listening post' for the analysis tool.

The advantages for using a hub are a low purchase cost, hubs are easy to use, and they install and uninstall quickly from the network. LAN hubs will only work in environments that run in half-duplex, you must break the connection to install and uninstall the hub, and they are good for analyzing a single station. This method can hardly be called Enterprise ready, but it's a great solution in the proper environment.

====
Network Uptime Surf Report
====

University of Buffalo Network Management Page

http://netman.cit.buffalo.edu/index.html

Jeff Murphy at the University of Buffalo has created a great repository of network management information, FAQs, and standards. This server also hosts the archive of the comp.dcom.net-management Usenet newsgroup. Although the server is rarely updated, the information contained in the newsgroup archives and software database is a great starting point for understanding more about network management.

====
Network Uptime Management Tip
Make Your Point With Cumulative Time Stamps
====

If you have to provide an explanation of network throughput to management, you many not want to explain specifics of a file transfer using the hex view of a protocol analyzer. In most cases, management just wants to understand the efficiency of the network in 'real world' terms.

Although it's not usually the default setting, most analyzers can show the total elapsed time for a process as a cumulative value. After filtering a trace to show a single transaction, the cumulative time-stamp can show that a process is taking seconds or minutes to complete. After making your point in real-world terms, you can narrow your focus to an inefficient process or 'chatty' application.

====
Ending Delimiter
====

If you're reading a forwarded copy of Network Uptime, sign up for your own FREE subscription:

http://www.NetworkUptime.com/newsletter/

Promote Network Uptime! Add Network Uptime graphics and banners to your web page:

http://www.NetworkUptime.com/graphics

To unsubscribe from Network Uptime, use the above URL, or email Majordomo@NetworkUptime.com with the following text in the body of the message:

unsubscribe NetworkUptime

For questions or comments, email us at James@NetworkUptime.com or visit the web page!

==== End of Network Uptime ISSN: 1529-6938 Issue 02 00 00 00 00 05 01 05 (c)2000, NetworkUptime.com, Inc. http://www.NetworkUptime.com ====