There was discussion about NIC HW timestamping on the NTP mailing list recently.
I didn't read the whole thing, but one of the issues that was brought up was "How accurate is the clock on the nic?". For very high precision, you'd have to discipline the NIC clock as well, so then you get twice the issues. Thanks, Erik -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Saku Ytti Sent: Monday, June 25, 2012 11:24 AM To: [email protected] Subject: Re: [c-nsp] NTP Servers On (2012-06-25 10:50 -0400), Josh Baird wrote: > And guess what the Infoblox appliances run? :) Earlier poster also wondered why waste money on "NTP appliance'. Some of these appliances have hardware timestamping, which will significantly increase accuracy, if your network is low-jitter and low-delay (like most HW switched networks today are). Curiously at least on ingress side your random NIC can support HW timestamping today, and IIRC even egress. Couldn't be arsed to surf intel.com through the datasheets. I wonder if the NIC HW timestamping function is flexible enough to inject timestamp in NTP packets as very first thing in ingress and very last thing as egress. And if there is way to give the NIC accurate timing somehow. Probably quickly becomes cheaper to buy some appliance than try to figure out how to hack this in NIC driver, possibly kernel and NTPd. -- ++ytti _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/ _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
