n00b question again

[Nick Withers]

On Sun, 4 Jun 2006 15:52:40 +0100 (BST)
dharam paul <exiaf_radar_guy38 at yahoo.co.in> wrote:

> Hello to all,
> 
> I was concerned about the security and bandwidth usage
> in my intranet. 
> The netstat -anW command gives me following output:
> 
> Active Internet connections (including servers)
> Proto Recv-Q Send-Q  Local Address          Foreign
> Address        (state)
> tcp4       0      0  192.168.1.14.22       
> 192.168.1.10.1150      ESTABLISHED
> tcp4       0      0  192.168.1.14.49988    
> 66.218.71.234.443      TIME_WAIT
> tcp4       0      0  192.168.1.14.56459    

(snip)

> It can bee seen that yahoo servers have established
> contact with my NIC (192.168.1.14]. Why so?

Or you've established a connection with a Yahoo server, which
is far more likely. I'm assuming you're talking about the
"66.218.71.234" (pclick1.data.ssl.scd.yahoo.com) connection...

> Is it valid?

You can see that the port on the Yahoo server is 443 (which is
used by HTTPS, typically) and the port on your machine is
high (above 1024). In order for a tcp connection to work, there
is a port dedicated to it on both the client and the server.
Typically, clients get / use high-numbered ports when
establishing a remote connection.

> Or is Yahoo using my bandwidth?

Depends on your point of view here! You're using Yahoo's
bandwidth, and it has to use your bandwidth to give you
anything back... So technically yes.

> At least one of the foreign addresses that have established contact
> with my NIC is that of Yahoo?
> How do I avoid it?

Firewall off Yahoo's IP renge(s)? :-)

> Please advise. TIA.
> 
> Send instant messages to your online friends http://in.messenger.yahoo.com 
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-- 
Nick Withers
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