[clug] How to prevent port forwarding

Kim Holburn kim.holburn at nicta.com.au
Sun Apr 23 04:49:16 GMT 2006

On 2006 Apr 23, at 1:41 PM, steve jenkin wrote:
> I would've thought that devices behind a NAT'ing firewall would be  
> invisible by definition:
> - there is no route to them, they are in a private world.
>  The external IP nr of the firewall is the only point that can be  
> reached by tools like traceroute
> - There is no TTL difference.  The firewall does not relay/rewrite  
> by packet, but by connection.
> - There is no host identifier - all internal IP's are mapped onto  
> the one external...

That's true but there are tools that can infer stuff in odd ways from  
the traffic coming from a system.  If you have access to all traffic  
from a site it's even easier.

Kim Holburn
Security Manager, National ICT Australia Ltd.
Ph: +61 2 61258620 M: +61 417820641  F: +61 2 6230 6121
mailto:kim.holburn at nicta.com.au  aim://kimholburn
skype://kholburn - PGP Public Key on request
Cacert Root Cert: http://www.cacert.org/cacert.crt
Aust. Spam Act: To stop receiving mail from me: reply and let me know.

Use ISO 8601 dates [YYYY-MM-DD] http://www.saqqara.demon.co.uk/ 
Democracy imposed from without is the severest form of tyranny.
                           -- Lloyd Biggle, Jr. Analog, Apr 1961

More information about the linux mailing list