dns.msftncsi.com DNS Requests Every Few Seconds

Over the weekend, I updated my wireless router to the latest revision of ASUSWRT-Merlin. I also decided to update my DietPi Pi-hole to their latest builds. Due to a full code rewrite of Dietpi, it meant a complete rebuild for that system. The release of ASUSWRT-Merlin also suggested resetting to factory defaults due to some major changes. Everything was about to be new again.

Once I got everything rebuilt and running, I noticed requests coming from my firewall to my dietpi every 10 seconds or so for dns.msftncsi.com. I immediately assumed this was some Microsoft telemetry noise on my network from MS NLA. However, the queries were coming directly from my firewall which seemed odd. Another search led me to a post on the Pi-hole discourse. After I ran nvram show | grep dns_probe, it was clear I found the culprit.

admin@gw:/tmp/home/root# nvram show | grep dns_probe
dns_probe_content= fd3e:4f5a:5b81::1

I ran the following three lines and confirmed the traffic stopped. No reboot was necessary. The first post I read recommended setting dns_probe_content to and dns_probe_host to “” (effectively blank). I later found a post by RMerlin that explains setting dns_probe_content to blank disables the watchdog service but effectively disables the dual WAN feature. It would make sense that dual WAN would require a watchdog service. So, if you use dual WAN, don’t do this. Otherwise, you should be fine.

admin@gw:/tmp/home/root# nvram set dns_probe_content=
admin@gw:/tmp/home/root# nvram set dns_probe_host=
admin@gw:/tmp/home/root# nvram commit

RPM/yum Database Corruption

Jumped onto my server and noticed a few out of date packages. A quick % sudo yum update reported the following:

error: rpmdb: BDB0113 Thread/process 12323/139745043400512 failed: BDB1507 Thread died in Berkeley DB library
error: db5 error(-30973) from dbenv->failchk: BDB0087 DB_RUNRECOVERY: Fatal error, run database recovery
error: cannot open Packages index using db5 - (-30973)
error: cannot open Packages database in /var/lib/rpm

Fortunately, the fix was easy:
% sudo rpm --rebuilddb

Once complete, yum update worked like new.

Weekend Reading – April 15, 2016

Blogs / News

Weekend Reading – March 25, 2016

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Weekend Reading – March 18, 2016

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Weekend Reading – March 11, 2016

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Weekend Reading – February 26, 2016



Weekend Reading – February 19, 2016

Fedora 21 on a Macbook Air

freedom-infiniti-fedoraAfter going around and around trying to get usb boot media working with my Macbook Air, I finally came across a gem that did the trick. I had an EFI partitioned disk and regardless of using Unetbootin, Yumi, and Lili, I was only able to boot just to receive this error:

error: file ‘/isolinux/vmlinuz0’ not found.
error: you need to load the kernel first.

The fix was to clean up my usb disk and then use Rawrite32. I found these instructions on the fedora project wiki under Windows Quick Start.

First, I had to blow away every partition on my usb device. Note: Take care to list disk and select the correct disk before running clean.

C:\> diskpart
DISKPART> list disk
DISKPART> select disk 1

Once completed, download and install Rawrite32. When you launch Rawrite32, select Open. You’ll have to hit the drop down to show all files so you can select the ISO. Under target, you should see your USB device to write to.  Hit Write to disk… and you should be ready to boot once it does it’s thing.