Who does source address validation? (was Re: what's that smell?)

Wed Oct 9 15:36:00 UTC 2002

On Tue, 8 Oct 2002, Greg A. Woods wrote:

> [ On Tuesday, October 8, 2002 at 22:34:51 (+0100), Stephen J. Wilcox wrote: ]
> > Subject: Re: Who does source address validation? (was Re: what's that smell?)
> >
> > 
> > So I guess you may argue block RFC1918 tcp inbound but icmp and udp .. you start
> > to break things, perhaps that is why large providers dont do this on backbone
> > links.
> 
> Such things REALLY _NEEED_ to be broken, and the sooner the better as
> then perhaps the offenders will fix such things sooner too, because they
> are by definition already broken and in violation of RFC 1918 and good
> common sense.

Ok but real world calling. I have tried this and when customers find something
doesnt work on your network but it does on your competitor you make it work even
if that means breaking rules.

You've snipped the other comments from my email which goes on to say take any
RFC for a protocol eg POP, SMTP etc and look at whats actually being done with
it, most commonly look at how Microsoft have implemented it or what the big ISPs
are doing on their servers etc and you either tow the line or your service
suffers.

Steve