NAT devices not translating privileged ports

Thu Jun 10 09:32:14 UTC 2021

Hi, Jean,

On Fri, 2021-06-04 at 08:36 -0400, Jean St-Laurent wrote:
> I believe all devices will translate a privileged ports, but it won't
> translate to the same number on the other side. It will translate to
> an unprivileged port. Is it what you meant or really there are some
> devices that will not translate at all a privileged port?

What has been reported to us is that some boxes do not translate the
src port if it's a privileged port.

IN such scenarios, NTP implementations that always use src port=123,
dst port=123 might be in trouble if there are multiple NTP clients
behind the same NAT device....

Thanks!

Regards,
--
Fernando Gont
Director of Information Security
EdgeUno, Inc.
PGP Fingerprint: DFBD 63E3 B248 AE79 C598 AF23 EBAE DA03 0644 1531