Private port numbers?

Wed Aug 13 20:10:05 UTC 2003

On woensdag, aug 13, 2003, at 21:38 Europe/Amsterdam, Crist Clark wrote:

> Cool. So if you use private ports, you'll be totally protected from the
> Internet nasties (and the Internet protected from your broken or 
> malicious
> traffic) in the same way RFC1918 addressing does the exact same thing 
> now
> at the network layer.

That would be the theory, yes. (I grant you that it won't be quite this 
simple in practice.)

> I'm sure everyone will filter private ports just as effectively as 
> RFC1918
> and martian addresses are filtered at borders now.

It's not the same thing. RFC 1918 and martian addresses aren't supposed 
to be present on the internet, but aren't automatically harmful. Having 
services that are explicitly labeled for internal use be visible to the 
rest of the world is potentially very harmful.