network performance analysis

Hello,


Recently I ran into a degrading situation on network performance:
my ADSL connection (512K UL/DL) even has problem to open a simple
HTML page now and then. I have a website serving friends for fun
with dynamic DNS. That could be used nowadays practically.
My friends outside my country cannot access the webiste even with
naked IP. I have a router behind the ADSL modem, accepting only 80
port data (no PING allowed). After several hours the router will
restart
( I set auto restart) which was not the case weeks ago. The router's
power supply was changed weeks ago.

I consulted my ISP, they told me that recently the Blaster virus
had some impact on the overall network performance, but it shouldn't
be that much. (OK, never believe them totally)

I remember once upon a time my website had been hacked with an
authentication
page, but seeing no intrusion to the computer and I guess the router
has been
masquraded.

I have a general question: what should I look into step by step to
resolve the problem(s)? Are there some good tools for me to gathering
data and do some diagnosis? I am not afraid of learning, even it
is tricky ;-) I will not decline changing the router or whatever
if the bottleneck found there.

BTW, I am about to advocate Linux locally (intro-tutoring at home)
and that's another reason that I should find a solution for the
network performance

And of course I am using linux, redhat 8.0. The router is a local
brand.
ADSL the same.


Thank you and best regards,
Wenjie

 

Something like ethereal will sniff.. could be handy?

 

Iptraf is good
http://freshmeat.net/projects/iptraf/?topic_id=152
Etherape will give you an interesting gui
http://freshmeat.net/projects/iptraf/?topic_id=152