NTP users are strongly urged to take immediate action to ensure that their NTP daemons are not susceptible to being used in distributed denial-of-service (DDoS) attacks. Please also take this opportunity to defeat denial-of-service attacks by implementing Ingress and Egress filtering through BCP38.See ConfiguringAudioRefclocksDev for discussion of this topic.
ntp-4.2.8p15was released on 23 June 2020. It addresses 1 medium-severity security issue in ntpd, and provides 13 non-security bugfixes over 4.2.8p13.
Please see the NTP Security Notice for vulnerability and mitigation details.Are you using Autokey in production? If so, please contact Harlan - he's got some questions for you.
# irig b (audio) # flag2 1 is line port, flag4 1 is verbose stats #server 127.127.6.0 version 4 #fudge 127.127.6.0 flag2 1 flag4 1 # wwv radio clock. time1 wwv, time2 wwvh, flag2 0=mike, 1=line. #server 127.127.36.0 version 4 #fudge 127.127.36.0 time1 0.0019 time2 0.00773634 flag2 1 flag4 1Here's my ntp.audio file:
idev /dev/audio0 cdev /dev/mixer0 agc line monitor volHere's a comment I made to myself with regards to a soundblaster live (pci) in a p133/freebsd host: jane4 (P133) with sb live wants rec 20 and agc rec (which seems to adjust line anyways) but it brings up IRIG With linux, I configure for ALSA audio fragment size with echo:
echo "ntpd 2 128" > /proc/asound/card0/pcm0c/ossTo actually debug the ntpd audio setup, build an ntp.conf with only the irig/wwv/chu driver, then "ntpd -D2" to get a view of the audio gain adjustments. I see things like this:
audio_gain: gain 139/54 audio_gain: gain 143/56..etc Note that some os/soundcard combinations simply Do Not Work with input, although their output might work. The devices I've had working here include a motherboard based C-Media PCI CMI8738, a PCI slot based soundblaster live, an ISA soundblaster awe64 gold, and a PCI slot based sb128 (ENS1371). OS include fbsd 5.3, fbsd 4.7/4.11, linux 2.4.20-NANO, linux 2.6.3 ppskit lite. Note that a PC in console mode (not running X windows or equivalent), can put a huge latency spike into the ntpd offsets when the console scrolls text down the screen. I suggest that the console not be used when running ntpd, and that you ssh into the computer to perform any configuration. Or you could run a window environment such as X (I'm a twm user myself), as the scrolling inside an xterm is a much less intrusive (to ntpd) operation than scrolling the bare console. It is best to not use a so-called "desktop" installation of the typical GNU/Linux distribution. These tend to pile on a number of programs that can interfere with ntpd's use of the audio drivers in the OS. If you can be sure that you have your "desktop" well behaved (I.E., not ursurping the audio), then try using ntpd and the audio drivers with your preferred distribution. I have tended to install a bare setup such as CRUX, with no "desktop" installed at all. Another example is a workstation running a redhat7.x (cough) release, but with none of its windowing stuff installed. Instead, I downloaded a more recent xorg X window system setup and compiled it for my particular environment. Both of these installations have run the ntpd audio wwv and irig drivers well. -- StevenBjork - 27 May 2008