November 15, 2000
Network Uptime - November 15, 2000
The Resource for Network Management and Protocol Analysis Professionals
A Newsletter of http://www.NetworkUptime.com
Issue 02 00 00 00 01 01 01 05
November 15, 2000
ISSN: 1529-6938
This Issue:
* Starting Delimiter - Wireless Holidays
* Uptime Report - A Propeller-Head Holiday Guide
* Surf Report - Wireless Resources
* Network Uptime Tutorial - Real-World Sniffing - Monitor Statistics
* Network Uptime Tip-Of-The-Month - Conserving Your Laptop Battery
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Starting Delimiter
- Wireless Holidays -
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I just received my 802.11b Wireless Sniffer software, and it is super-sweet. If you've not had time to do much research into 802.11b wireless technology, you owe it to yourself to check out some of the latest hardware and software. We've included a few links in this month's newsletter to get you started.
We've also added our holiday picks for the some relatively low-cost accessories for your LANs and WANs. Many organizations are slowing down for the holidays, and many budgets are closing at the end of the year. We've detailed some goodies that might be worth the effort of filling out a purchase request before the end of 2000.
This feature-packed newsletter also contains some Sniffer-related information on using the Sniffer monitor functions for real-world network analysis. We're building our library module-by-module, and we appreciate your ongoing feedback to the process!
I'll be busy this month with my wireless Sniffer. If you see a guy wandering around outside with an open laptop, you've found me.
- James 'Gigahertz' Messer
Editor, Network Uptime
James@NetworkUptime.com
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Uptime Update
- A Propeller-Head Holiday Guide -
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It's the end of the year, and many offices are winding down and preparing for the beginning of another year. During this season of paid time off, open employee parking, and weeks of absenteeism, Network Uptime presents the First Annual Propeller-Head Holiday Guide!
During the year, it's hard to find time to order those tools you NEED to make your job easier. It's in the budget, you've got the money allocated, and the new year is about to begin. Look through this list, and see if you are missing any of these important items.
Disclaimer: We are not telling you to spend your budget money without regard to the utility of these items. If you've allocated budget dollars to help the company succeed, then you owe it to yourself (and your team) to make the most of the company's money. If you don't need these tools, then don't buy them!
* Sniffer Operating System Update - Are you using the latest operating system for your Sniffer workstation? The latest Sniffer works under Windows 95/98 and Windows NT. A new version is due soon that will run in Windows 2000! Now may be the perfect time to purchase the latest operating system for your analysis tools.
* 10/100 Hubs - If you're using switches in your network, you may find that you need a hub to tap into an important link. Many companies make small hubs that could be stored in the same case as the Sniffer without taking up valuable space.
* Velcro Cable Ties - I love Velcro. However, many of the cable ties that I've seen are too flimsy to hold up to the rigors of data networking. Make sure the Velcro ties you purchase have the hook and loop down the entire length of the tie. You may want to look at the new Velcro Get-A-Grip product line, which provides a 3/4" width of Velcro that you can cut to length. Check your local office supply store for additional options.
* Label Machine - These battery-powered label-makers are all the rage, and they're just the thing for that rack of unmarked equipment. Even if your security requirements don't allow you to mark network addresses on your equipment, a 'Contact In Case Of Emergency or Questions' label might be prudent. Be sure to get a couple of extra label cartridges!
* Patch Cables / Patch Fibers / Jacks / Crossover Cables - You can never have enough patch cables or fiber patches. Check your inventory, and purchase enough cables to get you through the Winter months!
* Two-Way Radios - Most organization's networks are distributed throughout their campus or buildings. With today's Family Radio Service (FRS) radios, your organization doesn't need to be licensed with the FCC to provide your team with a quick method of communication when you're troubleshooting those campus-wide problems. WARNING: Be careful when operating any communications equipment near your network equipment (radios, cell phones, etc.). Stray RF can be potentially fatal to other electronic equipment!
* Digital Spread-Spectrum Cordless Phone - Most computer rooms are too large to easily troubleshoot a network issue while you are on the phone with the 'smart' people. If your computer or network area allows the use of cordless phones, consider one of the latest digital spread-spectrum phones for your facility. At the very least, consider replacing the wall and handset cords on your non-cordless handsets to allow more mobility in the computer room!
* Rechargeable Tools - Adding new networking equipment can be a labor-intensive job. Instead of calling the facilities department when you need a screwdriver, purchase some permanent tools for the computer room that are strong enough to help with the installation of the latest routers and switches.
* Cable Toolkit - Fiber networks may be the next-big-thing, but most of our networks are still copper-based. A toolkit with some basic cabling tools would help any network manager with physical-level issues. Purchase a kit that would provide punch-down tools, cable mapping tools, a toner, and other cable utilities.
* Power, Copper, and Fiber Meters - When a network problem needs a quantitative analysis, you'll need to have a tool that will provide numerical feedback for power consumption, copper cable NEXT, or fiber dB loss. These tools can be helpful when trying to get to the root cause of a problem.
* Extra Hardware - Check through your not-quite-a-disaster recover plan, and make sure you have replacement hardware for your most critical of systems. An extra processor module, interface, or CSU/DSU could be the difference between a profitable quarter and a loss on the books.
* Training Credits - Don't waste your training budget! Most training organizations allow the purchase of credits that you can use over the next 12 months. Find some good training classes, purchase the credits, and book the classes, even if they are six months away. You'll be glad you did!
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Network Uptime Surf Report
- Wireless Resources -
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Wireless networking is appearing everywhere, and our challenge is to keep up with the latest networking technologies. These links will provide you with plenty of reading for those cold winter nights.
The Wireless LAN Association (WLANA) is a non-profit educational trade association that maintains a great site for wireless tutorials, a directory of wireless products, and additional industry information. If you are just getting started in wireless networking, this is a great place to start!
http://www.wlana.com
Want to see the latest goings-on for the 802.11b Working Group at the IEEE?
http://grouper.ieee.org/groups/802/11/
You may also want to purchase your own copy of the specification:
http://standards.ieee.org/catalog/IEEE802.11.html
Although this web site is owned by Jim Geier's consulting organization (he's the guy who wrote the 'Wireless LANs book'), it has some great information on wireless networking. Be sure to view his comprehensive Online Guide to Wireless Networking!
http://www.wireless-nets.com/
3Com has a good introductory white-paper on 802.11b wireless technology. This basic overview covers the 802.11b technology and details issues to consider when building a wireless network.
http://www.3com.com/technology/tech_net/white_papers/503072.html
Network Computing produced a great article on 802.11b solutions in their July 10th edition. There's some great technical information and 'need-to-know' topics relating to wireless networking.
http://www.networkcomputing.com/1113/1113f2.html
Are you using Wireless networking in your organization? Send us an email with your wireless solution, and we'll feature it in the next issue of Network Uptime!
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- Network Uptime Tutorial -
Real-World Analysis - Monitoring Statistics
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We've added more 'real-world' monitoring tutorials in the last month, and we'll add the text to this newsletter. To view these tutorials with screen shots and additional content, hit the web site:
This month, we'll focus on the Protocol Distribution and Host Table monitoring statistics.
Although the next monitoring statistic in the menu and in the toolbar is the Host Table, the protocol distribution is the statistic that many network analysts prefer to analyze after viewing the dashboard statistics. The protocol distribution statistics provide a valuable breakdown of MAC-layer protocol families and sub-protocols within the IP and IPX families.
The Sniffer Pro protocol distribution can provide statistics of all of the popular MAC-layer protocols, including TCP/IP, IPX, Appletalk, SNA, Banyan Vines, and DECNet. The tabs at the bottom of the protocol distribution screens can also display statistics for the IP and IPX family of protocols.
Sniffer Pro comes pre-configured with some of the more popular IP and IPX protocols, but every network has a few applications that the Sniffer doesn't watch by default. To add your own TCP or UDP ports or IPX sockets, select 'Tools/Options/Protocols' from the Sniffer Pro pull-down menus.
All of the monitoring displays have options for displaying information in the monitor statistics. These functions change the view of the data to assist the analyst in interpreting the statistics, such as changing the graph to display bar or pie charts, providing the information in a tabular view, or exporting the information to a text file.
One of the keys to network efficiency is minimizing the unneeded protocols and making room for the protocols that help the organization function effectively. Almost every organization has some type of 'rogue' protocol running on the network, and often the network administrators are unaware that these unwanted protocols are running loose on their net!
One example of rogue protocols can been seen in today's 'plug-and-play' network printers or print servers. The network printer usually accomplishes this 'helpful' plug-and-play functionality by enabling as many protocols as possible during the setup process! In a TCP/IP-only environment, a printer sending IPX and Appletalk packets across the network is using valuable bandwidth that could be allocated to other processes. If the printers are also periodically broadcasting their presence, then every station in the broadcast domain is having to process those frames! This may not be a large problem when there are three printers on the network, but three HUNDRED printers can consume large amounts of network resources.
One of the questions that always arises when observing a protocol distribution breakdown is the 'Other' column. What is 'Other', and how does one find the mysterious 'other' protocol?
In the MAC-layer view of protocol utilization, the 'Other' counter refers to protocols that run at the MAC address layer, but do not belong to any of the other well-known MAC protocol families such as IP, IPX, or Appletalk. One 'Other' protocol is the Bridge Protocol Data Unit (BPDU), part of the 802.1d Spanning Tree Protocol (STP). The Bridge Protocol Data Unit is not part of any protocol family, so it falls under the 'Other' column of the MAC protocol distribution.
The value of the 'Other' statistic can sometimes identify inefficiencies on the network. For example, finding an 'Other' protocol at the MAC layer may lead to an investigation that uncovers BPDUs running on the network. Many networks do not have redundant switched links, and are unknowingly running STP on their network switches. A simple configuration change could disable Spanning Tree, which would remove the BPDU 'hello' multicast packet from traversing the network every two seconds!
Scrutinize your protocol distribution statistics, and you may be surprised at what you find running on your network!
Who goes there? The Sniffer Pro host table will tell you! When researching network issues, it's always important to know who is communicating on the network. The Sniffer Pro host table is a concise view of all workstations communicating on the network, listed by MAC, IP or IPX address.
The Sniffer lists any address that is communicating on the network, and can rank the communication levels in tabular or graphical form.
The host table allows each statistic to be sorted in real-time, so its easy to determine which workstation is sending the most amount of data. A graphical view provides the Top 10 Hosts, and usually there are one or two workstations who are doing most of the communicating!
Network slowdowns can sometimes occur when a workstation or group of workstations is using most of the bandwidth. In the host table view, it's easy to identify the top users! The tabular view lists the statistics in a text format, and each of the columns can be clicked to sort in ascending or descending order.
Some folks miss the Detail button on the Sniffer Pro vertical toolbar on the left side of the screen. This detailed host table view provides a breakdown of sub-protocols for each family.
If you're looking for a 'rogue' protocol or just trying to get an overview of the protocols running from individual workstations, the detail view can provide a lot of important information in a single table. Use this view to sort through workstations by protocol, bytes, or packets.
The Top Hosts graph puts network communication in perspective. It's easy to see graphically if one station is communicating four times more than any other station! The graphs can also be ranked by bytes in or out, packets in or out, or total bytes or packets.
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Network Uptime Tip-Of-The-Month
- Conserving your Laptop Battery -
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If you have a portable Sniffer, then you know that you are often running from closet to closet with your laptop, or you are using your laptop in areas where power isn't available. In those situations, are you using your laptop power efficiently?
* If your laptop supports multiple battery bays, purchase another battery to use simultaneously while Sniffing. Two batteries will last twice as long!
* If your laptop BIOS supports Advanced Power Management (APM), then take advantage of it! Load the APM software on your Sniffer laptop, and configure your laptop LCD, hard drive, and other power options. Be careful when using this feature, because some APM configurations will force your laptop into 'suspend' mode when there is no activity. You don't want your Sniffer going to sleep when you are working on a problem!
* Turn down that screen! The LCD screen is a big power drain, and the brighter the screen, the more juice you lose. If you are inside, you may be able to conserve battery life by setting the brightness and contrast a bit lower.
* If your laptop will continue running when you close the top, use this feature to turn off the LCD power when you are away from the machine. Even with the screen saver turned on, the LCD is still powered. Use this feature to completely power down your LCD!
* Is your screen saver 'busy'? If you use one of those crazy-line, three-dimensional, polygon-rendering screen savers, then you are using more power than you need! All of those screen savers use CPU cycles, which in turn require additional power. Set your screen saver to a simple black screen, and your batteries will last longer. These fancy screen savers also take CPU cycles away from applications, so you'll also be doing your Sniffer a favor!
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Ending Delimiter
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Posted by james_messer at November 15, 2000 02:06 PM