[clug] How to prevent port forwarding

Kim Holburn kim.holburn at nicta.com.au
Sun Apr 23 02:37:28 GMT 2006

I remember there was a guy who had a method to tell how many hosts  
were behind a firewall.  I just forget the method but I think it  
either was the guy who did all that weird stuff with indirect  
traceroute (using TCP related packets as traceroute)  I just can't  
remember the names of any of it off-hand.

Maybe fft:




On 2006 Apr 22, at 11:09 PM, Christopher Zhang wrote:

> Hi,
> I am interested to find out if it is possible, if so, how, that  
> some ISPs prevent 1 registered Internet user to distribute their  
> Internet connection by running their computer as a gateway for  
> other users to route through. The closest thing I can think of is  
> TTL, since if other hosts are routed through the legitimate host,  
> then their TTL will be at least be 1 less than if it were coming  
> from the legitimate host, without any artificial changes. Is this a  
> plausible way for ISPs ? Can anyone show me some iptables commands  
> that the ISPs would do? and also how can I change my TTLs and so on.
> Thanks
> Chris
> -- 
> linux mailing list
> linux at lists.samba.org
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Kim Holburn
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