DNS Shotgun is capable of simulating real client behaviour by replaying captured traffic over selected protocol(s). The timing of original queries as well as their content is kept intact.
Interconnection Quarterly
From Christian Koch from Foundations
I am excited to reveal that my quarterly interconnection update has
transformed into the Interconnection Quarterly, a hand-tailored,
independent briefing on the interconnection industry. Right now, my plans
are to publish the Interconnection Quarterly shortly after the last public
companies report earnings, as I’ve done with the previous updates. This
may change in the future, but for now, this is the plan.
In this inaugural issue, you’ll find the latest financial and business metrics
for select data center operators and interconnection platforms, as well as
insights into key developments and newsworthy events that occurred
within the fourth quarter of 2020.
We’re at an important juncture for interconnection, and while it still may
be seen by some as just a basic service that a data center or colocation
provider must offer, the truth is, that interconnection is much more
important.
From cross-connects to cloud networks, the constant here is in the
connection. How that connection is established and what you can do
with it is what’s changing as we adapt to a world powered by software in
the cloud.
Awesome CTO Github
Came across this gem in a newsletter.
https://github.com/kuchin/awesome-cto
A curated and opinionated list of resources for Chief Technology Officers and VP R&D, with the emphasis on startups and hyper-growth companies
Contents
- General
- Hiring
- Management
- Handbooks
- Development process
- Architecture
- Technologies
- Startups
- Related stuff
- Product
- Marketing
- More links
Common Building materials and dB loss in LTE
The following is an estimate of loss using LTE frequencies and common building materials.
-Fiberglass -2dB
-Drywall -4dB
-6″ Concrete 12-20 dB
-Brick -10-20dB
Bind 9.4 helpful notes
So recently I was spinning up some new authoritative names servers. I have stuck with bind for authoritative for years because the format of the files and queries is THE standard for DNS zones. IMHO, there are some better resolvers out there but I stick with bind for authoritative.
Anyway, on to my issue. The purpose of one of these servers was for reverse DNS. I added the in-addr files and added a few zone files. Things hummed along for a few days and the server went through an update and the authoritative stuff stopped working. After some digging here is what I found.
Bind 9.4 introduces a new option called
allow-query
allow query has specifically to do with the ability to query the namesever for records it is authoritative for. If that option is not there it will deny queries. Once I added the following code things started working correctly.
allow-query {any;};
A few later I come back to a different machine to troubleshoot an issue with a customer PTR record and found the log files were filling up with cache-denied messages. this was fixed by adding the two lines of code below.
additional-from-auth no;
additional-from-cache no;
In this case, some of the IP space still had servers pointing to it, most likely due to the domain holder going offline or out of business.
Server Tip from a non-server guy
Motherload of cambium webinar list
The following link contains a huge list of cambium webinars that have been archived by Cambium.
https://community.cambiumnetworks.com/t/webinar-archive/42455
Red-team Hacking tool
I wanted to do something with a Ras Pi Zero that would incorporate my love for red-teaming/offensive security, and I wanted it to take as many paths of least resistance as possible, and it couldn’t be super expensive ($50-ish USD). Now that I had the basic (albeit arbitrary) parameters in place, all I had to do was come up with the problem to solve. Think, think, think…
https://blog.itpro.tv/raspberry-spy-how-daniel-built-his-own-red-team-tool/
LibreNMS syslog.ibd cleanup
Recently I ran into an issue where a librenms install was taking up a crazy amount of disk space. This was tracked down to the syslog.ibd file . Even thought I had set my options to be less than 10 days per this link https://docs.librenms.org/Support/Cleanup-options/ I still was having a huge file.
Here is what I did to fix it. My root partition was too full to start MariaDB. I went into var and cleaned out enough log files to make space to start MariaDB. The following are tee commands I ran on CentOS 7 to fix it.
mysql -u username -p
Once at an MYSQL prompt after logging in I issued the following command to verify I could see my librenms database.
show databases;
The I issued
use dbname;
In may case it was “librenms”. Once connected to the database I ran the following command
DELETE FROM syslog WHERE timestamp < '2021-1-28 08:00:00';
This commands removes all syslog entries from the database before the date and time specified. In my case this was close to 40 GIG.
After I restarted MariaDB, ran .daily.sh and all was good.
Attack the slack
My friends over at FMC products have a good article on airflow in racks