[plug] cannot browse Internet

[Patrick Coleman]

On 2/26/06, Jon  Miller <jlmiller at mmtnetworks.com.au> wrote:
> Having some issues where all PC's (windows and Linux) cannot browse the Internet.  When I do a ping to any domain/website I get replies ok.  If I do a telnet I get a disconnection /cannot connect message.  Yet if I web browse to my ISP (Amcom) it brings up their webpage and I can do the same to bring my own up (across a VPN connection).
> Initially I thought it was our firewall, but for port 80/http request from the Cisco router we go directly to the Internet..  from the Office router and firewall I can telnet to port 80/http.
>
> I'm stumped as to what could be preventing port 80 requests.  Using ethereal I can see SYN packets only.  I can however see that something from my workstation is trying to contact kernel.org (although) this is on a Windows desktop (XPPSP2).
>
> I've done a scan for viruses and spyware, I can see that my anti-virus scanner is shutdown which makes me thing this is a virus at work.
>
> Any ideas would be greatly appreciated.
>
>
> Jon

I had a problem recently that sounds similar: I could ping out from
the computer in question but anything else (web, telnet) was not
happening. After spending about half an hour playing with route, pppd
etc it turned out that I had

iptables -P OUTPUT DROP

in my firewall script as part of an overzealous attempt to lock down
the system. Changing it to

iptables -P OUTPUT ACCEPT

solved the problem.

Not sure if you're doing anything similar, but I thought I'd point it out.

Cheers,
Patrick

--
http://www.labyrinthdata.net.au