Newbie problems with wlan - cannot access certain sites

vardhan · #1 11-12-2002, 09:49 AM

I am having problems accessing certain web sites from one of two laptops on my wireless network. eg. I cannot get to www.britishairways.com

I also have intermittent freezes when I cannot get to any site on the same computer.

The network is -
a Win2k laptop hooked up to BT Openworld ADSL (USB)
a Win98 laptop
a peer to peer WLAN using 3COM Wlan cards
Internet Connection sharing

The problem laptop is the Win98 machine that finds that the connection to the net intermittently freezes, and it cannot access certain sites as described above. Same problem with email (Outlook Express) - will go and get mail sometimes, other times it just sits there. Have to hit stop and then send and receive again. After several attempts it will perform....

I have no problems with sharing files or printers between the machines, and reasonable connection speeds most of the time from both machines. (upload speeds sometimes drop to 50-100kbps)

Any help would be appreciated
thanks

Greenstead · #2 11-12-2002, 01:34 PM

I don't use ADSL but there is a front page report on the adslguide website that may be relevant for your problem:

More news on general poor ADSL performance
This information addresses why choosing an MTU of 1458 for your connection results in better performance for a large number of people. The problem has been traced to the BT Remote Access Servers (RAS) that are Cisco based. Apparently if the packet size is less than 1458 then packets are simply passed on, but if the packet size if greater than 1458 then packets are inspected and eventually forwarded. Normally this is no problem, but at the busier times of the day this extra work on the larger packets can overwhelm the RAS servers and cause the slow downs that people are experiencing.
See this news post for more information on setting your MTU. For users that use Dial Up networking, then DrTCP is the simplest tool, and usually setting the Dial Up (RAS) MTU will fix things (this applies to most USB modem users).

You can find this and try DrTCP's tests at:
http://www.adslguide.org.uk/

vardhan · #3 11-12-2002, 02:27 PM

thanks for the tip. Unfortunately, even after changing the MTU value there is no change.

The problem is pretty consistent now - I cannot even get to practicallynetworked.com on the Win98 machine. I can however happily access google, yahoo, expedia etc.

I have tried to uninstall all firewall software on the Win2k machine, and that has no impact either.

I suspect that there is some issue with the network between the two machines, or else something in the ICS

When I connect up the Win98 machine directly to the USB ADSL modem I can access these sites with no problem!! The wireless network is still up under this scenario, and there are no problems with accessing the files on each machine.

Since Win98 does not have ICS, I am unable to test the whole setup in reverse.

Any other ideas?

Thanks
vardhan

BoteMan · #4 11-13-2002, 12:08 AM

It is possible that you have some kind of problem with the Domain Name Service setup on the computer in trouble.

When the failure occurs, see if you can ping raw i.p. addresses of known-good sites. You can lookup the numerical addresses of Yahoo or Google when things are operating normally or on a working computer, then perform the ping test when the failure occurs.

If the numerical addresses ping OK, then the problem lies somewhere in the DNS resolution. Either the first DNS server listed in that computer is failing to return data and delaying (freezing) operations, or there is some other DNS configuration trouble.

Try juggling the order in which the DNS servers are listed, or try a completely different DNS server to see if that clears up the problem. Of course, some providers don't want non-customers using their DNS servers so you might have to be persistent with the latter suggestion.

Good luck.

vardhan · #5 11-19-2002, 05:51 PM

Thanks Boteman,
Unfortunately, I cannot ping either the URL or the numerical address for these sites (including www.practicallynetworked.com) from the client computer (win98)

I am able to do so fine from the host (Win2k) that is actually connected using the ADSL connection to the web.

In any case, could you tell me how to find an alternate DNS?

If I connect the Win98 machine directly to the ADSL modem, the problems go away!! Unfortunately, the Win2k machine then does not have an internet connection!! (Win98 does not support ICS)

Thanks for your help

Vardhan

DaveG · #6 11-20-2002, 11:14 PM

I have had a similar problem to you and Im' using a very similar set up.

Two PC's (both running XP Pro), using Actiontec PCI 802.11b. The new PC has an ADSL modem and the old PC is sharing it over the wireless link. I also could not get some web sites on the old pc that the new pc could. I fixed the problem by going into the old pc's internet explorer settings and punching in the url and port of my isp's proxy server.

Hope this helps.

Dave

vardhan · #7 11-21-2002, 12:11 PM

Dave G
Thanks very much. It worked!!!
I am uncertain whether I have the right proxy server name etc - managed to find some on the net for BT Openworld.

Also, it takes ages for the site to open up to start with. After that it is fine!

Thanks again

Vardhan

DaveG · #8 11-21-2002, 12:36 PM

Glad to hear it worked.

Yes, it is slow for me too. A friend said that this is to be expected going through a proxy, regardless of the home network technology you are using.

I am a complete novice at any form of networking and I jumped in at the deep end a couple of weeks ago, trying to wirelessley network my PC's together.

I've still got one irritating problem left with my network, but I'm going to put that in a seperate post, to see if someone can help me, so watch this space!

Dave

tmayo · #9 11-29-2002, 02:42 AM

I am so close also to being totally networked...
Have precisely the same problem...with pretty close to same setup...I am using linksys cards
I use SNET (SBC) as my ISP (DSL).
any ideas on where I might find there URL and Port...
appreciate any input... as i am on my way to being totally networked..
TM

DaveG · #10 11-29-2002, 02:51 AM

Not sure I can help you there. I only found out about my ISP's proxy details by poking around their web site, and I found a section that I'd not found before. Hence my best suggestions to you are is to A) Do like me, and do some sniffing on their web site, or B) Call/e-mail your ISP's technical support line and ask them directly.

Dave

vardhan · #11 11-29-2002, 08:43 AM

I found it by searching in Google. My ISP said that they do not recommend using a proxy, but suggested using inputting their DNS server details in the TCP/IP properties manually rather than automatically.

tmayo · #12 11-29-2002, 01:01 PM

I assume i would get those from from provider...What am i asking for specifically...and where do i enter them...

Thanks

ted

DaveG · #13 11-29-2002, 05:57 PM

Ah! I'm with you now, that's really easy, so no fears!

Start up Internet Exploder, (ahem, Explorer)., and go:

Tools -> Internet Options -> Connections (tab) -> LAN Settings...(button)

The resulting dialog has two sections, the upper section is called "Automatic Configuration" and the lower section is called "Proxy Sever". Suprisingly enough, it's the lower section into which you can enter your proxy server url and port number!

Hope that helps you.

Dave