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I wrote down stuff I ran into

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kerberos

Kerberos for Windows, without AD

Continuing from the previous post, let's see what Windows can do with a MIT Kerberos based realm. Windows normally uses Kerberos as part of Active Directory, but it does have some basic support

  • Dan Drown
4 min read
kerberos

SSH single-sign on

I was looking for a way to deal with ssh/sudo authentication between multiple clients and multiple devices. I wanted something with a balance between convenience and security.

  • Dan Drown
8 min read
wsl

Mounting a dedicated disk in WSL2

In WSL2, the default disks are virtual. Microsoft has recently added support for mapping physical disks to your WSL2 VM. I was running low on space my C: drive, so I wanted to move some of my WSL2 data to a dedicated Linux drive.

  • Dan Drown
2 min read
bluetooth

Bluetooth Low Energy sensor, part 2

To continue from part 1: I want a wireless sensor that will last more than a month on 2x rechargeable AA or AAA batteries. Some ideas I have for what I could do

  • Dan Drown
1 min read
arduino

Bluetooth Low Energy sensor

I have some ideas for a low power wireless sensor.  I want something that will last more than a month on 2x rechargeable AA or AAA batteries.  I first tried an esp8266 and

  • Dan Drown
4 min read
wsl

Replacing the WSL Kernel

BackstoryI had a dual boot Windows/Fedora machine, and I wanted to be able to run the Fedora install as a VM inside WSL.  To do this, I needed the physical disk accessible

  • Dan Drown
1 min read
teensy

Teensy 4.1 ethernet

I'm a fan of the Teensy line of microcontrollers. I have a whole pile of them for various projects. When I saw that 4.1 was combining a 600MHz processor, 1MB ram, 8MB

  • Dan Drown
3 min read
ntp

Embedded NTP Server

Now that I got the results I wanted from my embedded NTP client, I wanted to convert it to an NTP server.  I also wanted it to support interleaved NTP mode, so it

  • Dan Drown
3 min read
ntp

Embedded NTP client/NTP interleaved mode, part 5

I'll test what happens when I plug my embedded NTP client directly into my NTP servers, bypassing the Ethernet switch.  This ends my long running embedded NTP client series. The systems involvedEmbedded NTP

  • Dan Drown
3 min read
stm32

Embedded NTP client/NTP interleaved mode, part 4

Part 3 ended with an unexplained 3us offset, this post will reduce that. Verifying PTP clock syncI wanted to measure the NTP client's PTP clock sync externally.  The PTP peripheral has the option

  • Dan Drown
4 min read
ntp

STM32MP1 NTP server, part 3

Previous posts: part 1, part 2, NTP client The NTP client confirmed that there was a 943ns difference between my two NTP servers.  Now, to investigate where it is coming from. ChangesI'll start

  • Dan Drown
3 min read
ntp

Embedded NTP client/NTP interleaved mode, part 3

Previous posts: part 1, part 2 In this post, I wrap up my embedded NTP client and use it to measure the difference between my other two NTP servers with hardware timestamps. Goal

  • Dan Drown
5 min read
stm32mp1

STM32MP1 NTP server, part 2

Previous post: https://blog.dan.drown.org/stm32mp1-ntp-server/ I figured out my offset problem, which was not a PLL problem like I thought. Connman has a NTP client enabled by default:(The distro

  • Dan Drown
2 min read
ntp

STM32MP1 NTP server

Previous post: Debian for STM32MP1 NIC Hardware TimestampsFirst step: enable hardware timestamps in chrony.conf: chrony configuration for hardware timestampsNext, enable chrony's measurements log, and verify it's using hardware timestamps (H) not kernel

  • Dan Drown
2 min read
arduino

Wifi NTP server

I saw a thread about someone who wanted a low power NTP stratum 1 server that could run off of batteries and could be put somewhere without an internet connection.  That had me

  • Dan Drown
4 min read
glibc

glibc/Linux DNS Round Robin

A friend was trying to figure out what glibc is doing with DNS round robin, and information about it is somewhat scarce.  He was expecting it to randomly chose an address out of

  • Dan Drown
2 min read
stm32

Debian for STM32MP1

I bought a STM32MP1 dev board because it has a gigabit NIC with 1588 PTP timestamps as well as hardware timers that can timestamp PPS events without interrupt latency and jitter.  I am

  • Dan Drown
2 min read
arduino

2 button keyboard

I wanted a simple keyboard with play and pause media keys to make it convenient to control my music. To handle the USB, I used a STM32F103 based "blue pill" board because they're

  • Dan Drown
2 min read
ntp

NTS part 2

Part 1: Packet format of Network Time Security I wanted to measure the overhead that NTS adds to NTP. To give a rough estimate, I modified the benchmark program included in libaes_siv

  • Dan Drown
3 min read
ntp

NTP security (NTS)

I've been hearing about Network Time Security (NTS) being in development for awhile now.  With Cloudflare's release of a public NTS service, I wanted to take a closer look at the protocol and

  • Dan Drown
3 min read
ntp

Embedded NTP client/NTP interleaved mode, part 2

Hardware transmit timestamps added to NTP client.

  • Dan Drown
2 min read
ntp

Embedded NTP client/NTP interleaved mode

NTP client with hardware timestamps

  • Dan Drown
4 min read
ntp

APU2 NTP server

I bought an apu2c0. I believe it will make a better NTP server than my other NTP servers.

  • Dan Drown
3 min read
ntp

RK3328 based NTP server

I got a ROC-RK3328-CC SBC because it has true gigabit ethernet, emmc, and USB3.  These are all better I/O options than the latest Raspberry Pi 3 B+. I put a SATA hard

  • Dan Drown
3 min read

TL-MR3020 NTP server, part 2

Part 1 was about the hardware, now for the software Step 1: pps-gpio-poll package This architecture doesn't support device tree yet, so it has a special pps driver.  The repo for the driver

  • Dan Drown
3 min read
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