Viewing profile — mlichvar

That's what the chrony tempcomp directive is for. But you would have to figure out the coefficients, it's not automatic. An advantage of constantly loading at least one core of the…

Current Debian, Ubuntu, Fedora, RHEL/CentOS (EPEL) have an ntpsec package, but no ntp package. It's not used by default (that's chrony on most of the distributions), but the users …

The major Linux distributions replaced ntp with ntpsec. A better question would be who is still running ntp. I know about FreeBSD and NetBSD. ntpsec as a project seems to be doing …

I agree with most of what you said. The author has other posts in the series where he tried to measure the accuracy relative to the PHC (not system clock) using PPS: https://scotts…

chrony can be configured to encapsulate NTP messages in PTP messages (NTP over PTP) in order to get the delay corrections from switches working as one-step PTP transparent clocks. …

On Fedora it is setgid screen, not root.

The Linux kernel keeps time as a 64-bit integer, but it's in nanoseconds, not seconds. It's a Y2262 problem.

Another way to look at it is that MIT gives freedom to the developers and GPL gives freedom to the users. It's a conflict between the two groups.

My current understanding of the wireless technologies wrt to home automation: - wifi is most reliable, secure, easiest to debug, but usable only for mains-powered devices due to hi…

To me that looks like they are reinventing NTP, but not addressing all the issues of PTP. A big problem with the PTP unicast mode is an almost infinite traffic amplification (usefu…

Here is a nice animation of reflections I found useful: https://www.youtube.com/watch?v=ozeYaikI11g

Fuzzing needs to cover all important bits of the code to be useful. The problem I see is that incomplete coverage creates a false sense of security. Projects have some minimal fuzz…

It's even less than that. Current OpenWrt versions work on devices with 8 MB of flash and 64 MB of RAM. OpenWrt 19.07 worked on 4MB/32MB devices.

A better solution to secure bootstrapping of time would be NTP+NTS (RFC 8915) using self-signed certificates with unlimited time validity, which can be preloaded with the OS and up…

A major problem in synchronization of the system clock is PCIe. Hardware can timestamp PPS signal or PTP/NTP packets with accuracy of a few nanoseconds if everything is well compen…

When you are comparing performance to kitty, are they both scrolling line by line (xterm's default), or jumping as with the xterm jumpScroll or fastScroll option?

> There's no networking hardware timestamp support for NTP because NTP has nothing to do with hardware timestamps. Both NTP and PTP don't care (as protocols) where the timestamps a…

No, NTP and PTP are two different protocols. They can both use hardware timestamps and reach single-digit nanosecond accuracy in ideal conditions. The main difference is in existin…

The article missed an opportunity to describe how spectacularly can things break when the 32-bit time_t overflows in Y2038. If you still have such a machine (preferably without any…

FWIW, from those 11 chrony CVEs: - 8 were found within the project itself (mostly by me) - none are memory-safety issues in the NTP-specific code - the last memory-safety issue is …

One issue with TV displays I didn't see mentioned here is glossiness. TVs are mostly glossy and monitors are usually matte. I strongly prefer the latter.

RFC 7808 specifies a TZDIST service. But most operating systems already have their own mechanism to update their timezone database. This is not a problem. Shifting timezones by 15 …

Some models that are known to work well with chrony are Intel I210, I350, and X550. Those don't care about the protocol as they can provide hardware timestamps for all received pac…

The unicast PTP support can be limited to boundary clocks and the enterprise profile doesn't require transparent clocks to support the unicast mode. Also, there are different types…