Filter NTP traffic by packet size?

Brandon Galbraith brandon.galbraith at
Wed Feb 26 17:44:55 UTC 2014

On Wed, Feb 26, 2014 at 6:56 AM, Keegan Holley <no.spam at> wrote:
> More politely stated, it’s not the responsibility of the operator to
decide what belongs on the network and what doesn’t.  Users can run any
services that’s not illegal or even reuse ports for other applications.
 That being said commonly exploited ports (TCP 25 for example) are often
blocked.  This is usually done to block or protect an application though
not to single out a particular port number.

Don't most residential ISPs already block port 25 outbound?

Blocking chargen at the edge doesn't seem to be outside of the realm of

More information about the NANOG mailing list