Common operational misconceptions

Masataka Ohta mohta at
Fri Feb 17 01:11:22 UTC 2012

Andreas Echavez wrote:

> *Why disabling ICMP doesn't increase security and only hurts the web* *(path
> MTU discovery, diagnostics)

That PMTUD works is a misconception.

> *How NAT breaks end-to-end connectivity (fun one..., took me
>  hours to explain to an old boss why doing NAT at the ISP level
>  was horrendously wrong)

That's another misconception.

While NAT breaks the end to end connectivity, it can be
restored by end systems by reversing translations by NAT,
if proper information on the translations are obtained
through some protocol such as UPnP.

					Masataka Ohta

More information about the NANOG mailing list