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.
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
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