is there a good reason for this type of networking trouble ?

well .. first of all I want to say hi to everyone in this forum.
And forgive me for my poor english ..

When I've got problem with networking, I ask google and come up to this website .. and most of the suggestion on this forum threads solve some of my networking problem.

I'm wondering is there any good reason on this type of question.
I used ADSL connection, IPCOP for my proxy, and XP Home on client.

I can't browse some of websites from my network such as mail.yahoo.com ; hotmail.com ; friendster.com .. etc

I tried to ping with my console , it replied and there's no problem with pinging.

I tried trace route websites that I told before, it replied and it shows how many hops to that website.

on the other side, at home I used cable connection and there's no problem browsing websites such as mail.yahoo.com ; hotmail and friendster .. etc

The question is,
is there something wrong with my network configuration ?
or it's my ISP problem ?

I'm really sorry if there's already have this kind of topics in this forums ..
But , any suggestion are welcome ..

Thanks in advance ..

regards

Welcome to firewall.cx, bryu. Are you talking about two different networks? I ask ask this because you stated that there were no problems browsing from home but that you had problems browsing from a network. Let us have the details of both systems/networks.

ok ..
it's like this
At home I used cable connection, there's no problem with cable connection when I browse that kind of site.

At office, I used ADSL connection with IPcop .
here's simple drawing of my office network


[code:1] Internet --- ADSL modem --- Ipcop -- Switch -- Client Computer[/code:1]

the weird thing is, I called the ISP and I asked them to browse i.e mail.yahoo.com , and they didn't have problem with that.

And then I tried to bypass the proxy and make my network look like this.

[code:1] Internet -- ADSL modem -- Computer Client[/code:1]

Still no go , I wonder why ..
If I can ping the website domain perfectly 0% packet loss, but in the other hand I can't browse from any of my web browser.
I also tried enabled cookies, cuz I think website like yahoo required browser cookies to be enabled. but still failed ..

and another thing ..
the first day I used the ADSL connection, there's no problem browsing that sites . but today ( 5 days after ) it always failed ..

I'm really appreciate for your help / suggestion ..

Let's try to break this down into logical chunks.
First, forgive me for the obvious question but you haven't actually said that you are using the same client PC at home and at the office. I'm assumimng that you are.
Next, you seem to have DNS resolution okay since you can ping websites by name.
If it is the same PC at home and at work then there can't be anything wrong with your browser. So, although I can't see what, I wonder if something is blocking port 80 here.
Try opening a DOS box on the PC and typing
telnet www.siemens.co.uk 80
If the DOS box goes blank and you get little white bars down the left hand side when you hit enter, you have successfully connected on port 80. Note that this trick won't work with all websites; most have it blocked

Hi

Let me try for a "If ... Then" type of trouble shooting..

1. If you are able to ping the Domain Name like mail.yahoo.com this means, you proxy server is allowing you to send packets and so as your ADSL Modem.

if Not >>> are you able to ping the P address of mail.yahoo.com (66.218.75.184).. If Yes then on your Win XP PC, assign a manual DNS address like 38.9.211.2 or 38.9.221.2

2. If your Ping to the Domain Name works but ot thru the browser, can you try with any other PC..

If u see the same problem with other PCs too then check for any WebSite Blocking setting over HTTP in your IPCOP Proxy or ADSL Modem...

3. Also please let us know the Make & the Model number of your ADSL Modem..