A Technical I.T./DevOps Blog
Question
Some companies are getting away from VPNs in favor of zero trust systems. It can help save money on bandwidth and facilitate a better network performance when every employee is working remotely. Are NoVPN Services More Secure for a Given Enterprise? Is it recommended to use non-VPN services?
Answer
We think this is a debatable whether VPNs (Virtual Private Networks) make systems more secure.
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Continue reading “Are Zero Trust Networks More Secure than VPN-Protected Networks?”
Problem scenario
You are installing CentOS 8.x but when you click on the “Installation Source” tab, nothing happens. You do not see an option to enter an installation source.
You cannot click “Begin installation.” What do you do?
Solution
Try different installation media. If you are using a boot.iso, this problem may happen.
Some DVD isos are here: http://ftp.hosteurope.de/mirror/centos.org/8/isos/x86_64/
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Problem scenario
You are using WordPress for you website. You have code that has an indentation of one to three spaces that you do not want. You did not intend for this indentation. It is usually just one line — the top line.
Here is an example:
How can you eliminate this indentation of your code?
Solution
Root cause
If you have a new line in the paragraph,
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Continue reading “How Do You Eliminate Unintended Indentation in Code?”
Question
It seems like “global” and “nonlocal” would be the same thing. How are these keywords different in Python?
Answer
Variables inside a function are local by default; variables outside of functions are global by default. (This was taken from https://www.programiz.com/python-programming/global-keyword.) This answer/article addresses the “LEGB lexical scoping rule” (taken from page 872 of Learning Python).
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Continue reading “What is the Difference between global and nonlocal in Python?”
Problem Scenario
An automated process is failing. You look in the logs and they don’t help you. You have Googled the error. What should you do?
Solution
Has it ever worked? If so, did something change?
If not, Google for the command most recently entered before the error happens. New characters could be added into the command that you do not realize.
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Question
In computer programming, what is memoization?
Answer
Memoization is the act of pre-computing or pre-processing certain values for the sake of an algorithm’s performance. Rather than perform the same exact operation (which could be very complex and computationally expensive) multiple times, memoization will involve writing code to compute it once and store it in memory as a variable. This optimization can allow the call stack to have less to store (e.g.,
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Question
You want to know discretely what the third way of the three-way handshake is in the context of TCP/IP networking. What is it?
Short Answer
It is the sending of a TCP packet with a flag of “ACK” from the client to the server/destination.
Longer Answer
The third way is sending a TCP packet with the “ACK” flag (of which several potential flags are possible) to the destination:
Client —–>
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Continue reading “What Is The Third Way of the Three-Way Handshake?”
Question
You want to know discretely what the second way of the three-way handshake is in the context of TCP/IP networking. What is it?
Short Answer
It is the sending of a TCP packet with a flag of “SYN-ACK” from the server/destination to the initiating client (after the first way was completed).
Longer Answer
The second way is sending a TCP packet with the “SYN-ACK” flag (of which several potential flags are possible) to the destination:
Server —–>
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Continue reading “What Is The Second Way of the Three-Way Handshake?”
Question
You want to know discretely what the first way of the three-way handshake is in the context of TCP/IP networking. What is it?
Short Answer
It is the sending of a TCP packet with a flag of “SYN” from the client to the server/destination.
Longer Answer
TCP is used in HTTP communications. TCP uses a three-way handshake;
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Continue reading “What Is The First Way of The Three-Way Handshake?”