IPv6 and IPv4 - how to shut off IPv6?

[aluminumsulfate at earthlink.net]

> Date: Sun, 01 Apr 2007 15:48:34 -0400
> From: Bruce Labitt <bruce.labitt at verizon.net>

> As a result of the mythfest install, my computer was setup with FC6.  

Go you!

> outside world are excruciatingly slow.  (Connection to google takes 
> minutes, other computers on the same network, seconds.)  I do know that 
> my router does not like to pass through IPv6 info, so I am suspecting 
> something like this.
> 
> Are there some tools I can use to determine what is actually happening?  
> Firewall or traffic analysis?  If someone could show some sort usage it 
> would be greatly appreciated.

Try:
 $ host www.google.com # watch how long this command takes
 $ IP=10.11.12.13 # make note of one of the IP addresses returned
 $ ping $IP # look at packet loss ratio
 $ traceroute $IP # look at latency

That should at least give you an idea of *which part* of "connecting
to the outside world" is bogging down.  Then, you can run a protocol
analyzer (like the infamous tcpdump) to see what's taking so long:

 # tcpdump -ni eth0 # -n supresses reverse-DNS lookup, which could be confusing

Interpreting the output for things like ping traffic is fairly easy.
For other traffic, you may need a modicum of knowledge about how the
individual IP protocols work.