Troubleshooting WLAN

[dxb]

Hi to all,
Im an IT guy who venture into wireless networking few months ago and i just want to know some good advice,tips and a good website that deals mainly on troubleshooting wireless network. The thing is, everytime i want to fix a wireless lan, i dont know where to start unlike the wired one, the PING command and the connection of cable, type of cable and driver for the NIC is all that matters to start troubleshooting and eventually fixung the problem. I know the SSID, WEP WPA and those other technology that comes with WI-FI and all those a/b/g and stuff, but im quite dumb when problem starts. i usually encounters the Intel 2200 wireless card that comes most of the Laptops today, the ACer, Toshiba, Fujitsu, just to name a few, and all i can do to troubleshoot it is to update the driver but most of the time it didnt work so i have to go to the settings of access point, usually a 3com and a linksys gateway, to figure it out and after which, im dumb.
hopefully you guys got my point. The bottom line is that i want to know a step by step process to profesiionaly solve each wireless connectivity problem.

Thank you.

[Variable]

The bottom line is that i want to know a step by step process to profesiionaly solve each wireless connectivity problem.

When you get this, you should write it all down carefully into a book. I will buy it.

[jimmy5k]

personally i'd start with

"what kind of wireless network is required, wireless router or AP or simple ad hoc network"
or if you're new to a network (you have to work on it) how is it locked down?
*Mac Addressing?
*Password?
*Hidden SSID?

then "is the wireless unit within range/recieving" (usually you need to have a wireless card and be able to see its SSID)

network stumblers are very handy tools for this.


if theres performance issues, it could be due to signal strength or someone with a lower grade card affecting performance.
Some D-Link 802.11b can reach 22Mbit speeds but only if all products are Dlink 802.11b. also an 802.11a/b/g router will automatically drop to the lowest network speed. if you have all these devices operating on 802.11G and someone connects with an 802.11b card, your network will drop to the 802.11b speed. all of it.

theres many things to consider. faraday cages, ranges, Line of sight (not so much for a household wlan)

ultimately when developing a wlan, security is important, but its more important to get it up and working before locking it down. like all technical repairs, its best to start as simple as possible. you have your main wireless device, and then you have your connecting wireless device(s).

after the computers all connect, then you can go ahead and troubleshoot ip addressing and so on. there will always be some lag on the network.

is there anything else? feel free to add.
I always try to help
some people may disagree with some of what i have said but i'm open to suggestion/"CONSTRUCTIVE" critiques

[FastLearner]

I don't see the difference. Since all of these network media types (cabled or wireless) all operate at the same level of the OSI model, I don't see why the problems should be approached much differently. Wireless NICs still have link lights to check, PING works the same way, and IP addressing is the same in a wireless network.

What you are looking for is a standardized approach to trobleshooting networks, which is something I inquired about a while back. The sad fact of the matter is that no two networks are the same, and therefore they all require different troubleshooting steps.

Sure with wireless communications, there is usually another level of complication involved, such as encryption. As a general rule, I usually disable all encryption (WEP, WAP, etc.) and firewalls when dealing with connectivity issues, if that helps any. Usually if you have good connectivity, then moreoften than not you have an IP addressing or DNS server issue - notice I said usually, as there is unfortunately no "always" when it comes to network troubleshooting.

A great place to start is to ask a lot of questions when you run into an unfamiliar problem, and this forum is a great place to do it. There are many here who are very experienced in this area (PrntRhd, Classicsoftware, Paul Komski just to name a few) who will be more than happy to help you through any hurdles.

[bubbah]

hey learner...I see at the bottom of your post some spyware links...here's a good one for you (OFF topic) ...spybot suddenly now does not proceed with the scan...the software shuts down ...I uninstalled it and reinstalled it. It seems this happens since the M$ Antispyware updated to the latest beta a few days ago ...what happened? It does start, download latest defs, and will immunize ...but will not scan...how come?

[FastLearner]

Hi Bubbah. Please start your own topic for this in Applications and Security, (including a most recent HijackThis scan of your system if you want).

I am really not sure what you mean by:

It seems this happens since the M$ Antispyware updated to the latest beta a few days ago

Are you suggesting that there's a connection there somehow?

[dxb]

ok.. lets go back on track...

[dxb]

I don't see the difference. Since all of these network media types (cabled or wireless) all operate at the same level of the OSI model, I don't see why the problems should be approached much differently. Wireless NICs still have link lights to check, PING works the same way, and IP addressing is the same in a wireless network

the difference is on the physical layer. with wired network you can always check the cable it its faulty or not.. is there any such device where you can test the frequency or something just to tell you that your pc or laptop are still receiving a signal or not? we are not talking the technology behind but some approach on troubleshooting a wireless network. If you can give me some link on some great free utility outthere who can sense any problem as far as wireless network is concerned, that would be a nice stuff to begin with.

[FastLearner]

There is no utility or machine that works better than the ping command, in my opinion. This is how you can check for connectivity, whether you are using a wired or wireless solution. Before you do, however, you should disable all firewalls (make sure to turn them back on after the problem is solved) and eliminate any other things that complicate the issue (this holds true for wired networks, as well). Incidentally the best way to troubleshoot a wireless network, and I am not being a smart alek here, is to turn it into a wired network first. I always recommend having at least one node on a wireless network that is wired, and this can be your lifesaver when the time comes to troubleshoot (or reconfigure the router) comes. Then you can eliminate the possibility of one of the wireless NICs or other wireless devices being responsible for the problem.

[Paleo Pete]

The ipconfig and netstat commands might be helpful too. Ping is your best buddy though, if you can get a ping reply the hardware is OK, it's then just a matter of getting the configuration lined out.

Always check device manager for conflicts or driver problems, and a laptop that you know is setup correctly might help as well, if it can connect and get a ping but nothing else can, you know the problem is configuration and not hardware or signal strength. Setting it up is not hard, just give it the right workgroup name and carry on. The rest of the configuration should usually stay as is, get an IP address from the server, no WINS resolution, etc.

[dxb]

Thanks for your opinion guys. i came a cross with a utility called netstumbler and it seems a nice utility that you can use with wireless network. this is the thing Im talking about and eventhough i havent tried it yet, at least you already got my point. The problem with wireless is not on the advent of configuring it but after and base on my experience so far, most of the laptop with built in wireless card just suddenly stops receiving any signal after quite sometime and that where my problem begins. Normally, I just start with what pete suggest, the thing is that it doesnt look as easy as the wired one since you are dealing with those stuff that you cant barely see, frequencies! :)