Basic network troubleshooting

Whether you are putting together a network of five computers or 50, there are some things you need to know. During this Guild Meeting, John Day showed us the ropes of troubleshooting.

Networking computers can be difficult whether it is with five or 50. John Day led us through some troubleshooting in basic networking that might just save your day. If you couldn’t join us then, enjoy the transcript. We hope to see you on our next live Guild Meeting. You can find a schedule of Guild Meetings in your weekly TechProGuild Notes TechMail or on the Guild Meeting calendar.

Networking computers can be difficult whether it is with five or 50. John Day led us through some troubleshooting in basic networking that might just save your day. If you couldn’t join us then, enjoy the transcript. We hope to see you on our next live Guild Meeting. You can find a schedule of Guild Meetings in your weekly TechProGuild Notes TechMail or on the Guild Meeting calendar.

Note: TechProGuild edits Guild Meeting transcripts for clarity.

Good afternoon, everyone!
MODERATOR: Greetings! Welcome to this afternoon's meeting. Today network guru John Day will do a network troubleshooting Q&A. Take it away, John Boy... sorry.

JOHN DAY: Thanks. Before I go off on a ramble, does anyone have any specific questions or any problems with your network that you'd like to discuss?

JHORTON: I am curious about cabling problems that can occur, i.e., running cables over lighting fixtures, etc.

JOHN DAY: Well I recently learned that one of my habits might cause problems.

76327711: One of the applications we work with uses the Pervasive DB manager and seems to have trouble/conflicts in NetWare and NT environments. Is there anyplace with a "complete" guide to Pervasive other than their official site and support?

JOHN DAY: That is I used to leave 10 feet of slack in the ceiling when running cable and coil it up for possible future moves. This can cause magnetic interference and loss of signal quality; light fixtures are the worst but only for fluorescent lights.

76327711: When running your cabling, try to avoid anything that can cause or initiate electrical interference. This is just common sense.

JOHN DAY: I used pervasive SQL for NT without a hitch. So I didn't need many support contacts. Have you tried a "google search" or better yet, I use bullseye's search engine with great success.

Seek and you shall find
76327711: Interesting about the cable coil. I just read some installation instructions for a product that was very specific about the problems caused by coiling cable. Never thought about that as a problem before.

JOHN DAY: I learned it from an expert while working for TechRepublic. I had done it for years without a problem, but he showed me the specs.

JHORTON: Then my options are to either use the exact cable length for each node or snake the excess length in the ceiling somewhere?

JOHN DAY: Yes, I would just rely on longer patch cords and skip the snaking for the sake of neatness.

JHORTON: Good idea.

JOHN DAY: But I still leave slack on the head end above my racks. I like to reorg my data centers during slow periods. Did that not work Joan? Or do I need to do that each time? While we are waiting, have you guys tried netsonic? It really does speed your Internet connection. For caching, MTU, and DNS local storage, it rules.

76327711: Oooo, we're an inquisitive group. Seems like a first date: strangers sitting across the table from each other trying to figure out what to say and not seem too stupid.

JMOORE: Where can I get it?

76327711: Does it do anything to improve DSL connections or just dial-up?

You can do magic
JHORTON: I used it for a while; it seemed to speed it up drastically.

JOHN DAY: I got it from a offer. Let me look up the address. Yes, it has settings for dialup, cable modem, and DSL. Yeah the free version is a drag because you have to keep refreshing pages, but once I paid for it, I notice about a 25% pickup. So back to network troubleshooting. The only really difficult problems I found that couldn't be solved with ping, netstat, or some other TCP commands were usually related to DHCP and WINS. Obviously these either only affected MS networking while TCP ran fine or the opposite, depending on which caused the error. If you have one or the other, then WINS or a rouge DHCP server on your net is most likely the problem. Hey, you can get a rouge DHCP server on your net if you have users experimenting with NT. Most of the other issues I've seen were bad connections or bad hardware, which are pretty easy to track down, unless of course you’re talking about Web sites or servers; then, you have a whole new set of issues. Performance problems are more difficult to solve than loss of connections. You'll spend a lot of time doing trace routes and trying to find bad switches, VLAN configs, or routers to solve them.

JHORTON: Sorry to change the subject, but is there any demo or free software that can detect and notate any and all devices on the network for tracking purposes?

JOHN DAY: I used HP Openview and its autodetect feature with success, but you have to allow for increase traffic during its discovery phase. And no, it's not free. There are some cheaper packages, though. I just haven’t used them.

It’s okay to be cheap
JHORTON: What price range are we talking about?

JOHN DAY: Let me flip pages, and I'll see if I can find something quick. Here is the link for netsonic Internet "booster":

MODERATOR: Fyi fyi fyi ( I hate that), we're at the half-way point for this meeting.

JOHN DAY: Seems like I found a product that discovered network devices that cost a few hundred dollars. I believe it was like a Visio Technical with a discovery feature.

JHORTON: Thanks, I will investigate.

JOHN DAY: It was Visio Enterprise. I thought I tried it, but it did work with some tinkering. I think it is like $500 now. But it draws network diagrams almost by itself.

JHORTON: Does it work on WANs, or is it dependent on passwords, etc.?

JOHN DAY: If you've named your workstations, servers, and other devices’ names that mean something to you, then you don't even have to add titles. It will work on WANs, but it does take some time if they are large networks. And if you have firewalls, then passwords can be an issue, but I've not tried it in that environment. I used HP Openview because it came free with my Cabletron HUBS and allowed me to diagram, monitor, and troubleshoot from one interface. I don't know if cabletron still gives it away or not.

JHORTON: In a small network environment (20 to 30 users), is a switch replacing a hub going to make any noticeable difference in performance?

JOHN DAY: It can if you segment it correctly, or it can cause problems, too. Allow time to learn about VLANS and set them up to truly segment traffic. Cut over on the weekend because misconfiguration can bring you down. If you have workgroups, then setup VLANs for them and connect them virtually together to reduce broadcasting.

JMOORE: Is the performance increase worth the cost and time to switch?

JOHN DAY: If you just have one server and don't do peer-to-peer filesharing, the difference isn't worth it in my opinion. But even without VLANs, it does cut down on chatter. But I would start with basics: eliminate NETBIOS traffic, go only with TCP/IP, and use subnets to segment traffic if you have performance issues. But switches are a plug-and-play way to accomplish some increases in performance.

JHORTON: VLANS? Any recommended books or sites to visit?

JOHN DAY: But if it came down to blocking MP3s and streaming video to my users or buying new switches, I would buy the hardware. I would try Cisco's site and I'd buy Cisco, but that is just my opinion. 3com may have information also. I've tried to configure both, and Cisco gives you a nice book that is pretty easy to follow. Plus you can put CISCO on your resume. You could always search TechRepublic and TechProGuild….

JMOORE: How well do the drives that just plug into the LAN work. I was wondering how it compared to a real file server.

If at first you don’t succeed
JOHN DAY: I've tried it once, and it worked very well. I just prefer to buy my servers with enough room to add drives directly. I think it reduces transfer rates if your application and data are local to the processor. But if you don't have raid cages in your server with room to grow and don't want to buy a new server, then they work fine. I've only used them in NT, so I don't know about mounting remote drives in NetWare. I just did a search and Planet Cisco seemed to have some good VLAN info. Don't know if it is free or not. And if I were going to add network drives, I would add one switch and setup a VLAN between it and the fileserver or any clients that are going to be heavy users to get a dedicated 100-Mb pipe.

MODERATOR: Thanks, John, for taking time to answer questions today. We really appreciate it.

JOHN DAY: Let me know if you try that Visio Enterprise 5.0. I haven't tried the new version. (

JHORTON: Will do.

MODERATOR: Thanks all for being a part of this Friday's Guild Meeting. See ya next time... same bat time, same bat channel...

JOHN DAY: Well until next time... Happy Trails....
Our Guild Meetings feature topflight professionals leading discussions on interesting and valuable IT issues. You can find a schedule of Guild Meetings in your weekly TechProGuild Notes TechMail or on the Guild Meeting calendar.

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