Can't surf and email

[daYz]

Hi,   I had my internet connection working for a while on Redhat 8.0, but yesterday I suddenly couden't email and surf anymore. At the time it stopped I was trying to setup my local network, but I'm not sure if this got something to do with it. I have tried to deactivate the local network card on my computer, but this doesn't seem to help. I have also tried to disable my firewall (the redhat firewall), but I can't seem to change the settings. The firewall keeps the setting at high no matter what I try. Does anyone have an idea what the problem could be? How can I adjust the settings of my firewall?   My modem is an Alcatel Speedtouch USB, and I can ping and traceroute computers on the internet.   Thanks for your help.   Ben