What are other’s doing at a network level, if anything? I’ve been mulling over the idea of using L4 Redirect on Cisco ISG profiles to transparently redirect all customer NTP requests towards our NTP servers, which will then allow blocking NTP traffic upstream except to our NTP servers. It’s possibly a little controversial to transparently redirect NTP, but we’ve had DNS redirection in place for over a year now and not a single complaint. We put that in place to tackle people using the likes of OpenDNS/Google DNS then complaining when CDN performance sucked. Prefer to avoid L4 redirection if possible though given how intrusive it is but for most of the customers I’ve looked into on our list of open NTP addresses we don’t control their CPE and trying to get them to sort it out has proven difficult. -Scott ________________________________ The content of this message and any attachments may be privileged, confidential or sensitive. Any unauthorised used is prohibited. Views expressed in this message are those of the individual sender, except where stated otherwise with appropriate authority. All pricing provided is valid at the time of writing only and due to factors such as the exchange rate, may change without notice. Sales are made subject to our Terms & Conditions, available on our website or on request. ________________________________