How to download SSL/TLS certificates in C#

How to download SSL and TLS certificates in CsharpThis article is about how to download (or save) SSL/TLS certificates from any server by use of C#. Although nowadays certificates can be stored quite simply from the web browser, this is always associated with quite a few clicks. And at the latest when you want to store certificates from mail servers, etc., i.e. systems that can not be addressed directly in the web browser, a programmatic solution, as shown in this post, may be the easier way.
All in all, I would like to introduce two variants today. One variant, which works only for HTTPS connections and another variant, which works for all TCP connections (like mail servers, etc.).
Download HTTPS/SSL certificates in C#
The first addressed solution works only for HTTPS connections and is […]

How to read, calculate and set MTU in Windows, Linux and OSX

After I released the MTU Optimizer, a small tool for determining the optimal MTU, some days ago, let’s look at how to determine the optimal MTU by hand, how to read the currently set MTU and how to set new MTU value now. Of course we will discuss the whole thing for the three major operating systems: Windows, OSX and Linux.
Before we look at the implementation within the individual operating systems, we first briefly clarify what the MTU is and how its optimal value can be calculated.
Theory – Identify ideal MTU
The MTU (Maximum Transfer Unit) describes the maximum packet size of a protocol. It therefore indicates the maximum size of a data packet, so that it can be transmitted via a protocol. If a data packet is larger, it becomes fragmented – i.e. divided into several packages.
For example, let’s assume that we (=PC) would have a factory for sugar packets and our packet […]

How to fix “There was problem sending the command to the program” error

Bugfix solved how to fix there was a problem sending the command to the program errorThis article is about how to fix the annoying “There was problem sending the command to the program” error, which may occur in various Microsoft Office products. Yes, the title of this article is bulky – but it hits the core.
This error can occur in various Office products such as Excel, Word or PowerPoint and shows as follows: For example if you try to open an Excel file by double-clicking the Excel application starts, but displays the error message instead of the file. However, opening the file from Excel via “File -> Open” still works.
Error sending the command to the program

Tool: MTU-Optimizer – automatically find the best MTU

Today I would like to present you again a small tool from “own production”. The tool I’m talking about is called MTU-Optimizer. The name already gives an indication of what the tool can do for you: It determines the MTU (Maximum Transmission Unit) and can set it for any network card.
Like most of my tools, the MTU Optimizer is programmed in C# and designed as portable application. (This means: It does not require any installation and can be started, for example, from a USB flash drive.) The download link to the tool can be found at the end of this article. Beforehand, however, I would like to briefly discuss the capabilities of the tool. Therefore we should first have a look at what the MTU is all about.
What is MTU?
MTU is the abbreviation for Maximum Transmission Unit and is the maximum packet size within a protocol. If the data packetsize exceeds […]

Hot to show MySQL database size via SQL statement

Calculate MySQL database size via SQL statementToday, there is only a very short article with an SQL statement which allows you to display the size of a MySQL database, as well as the description of how to read out the database size via phpMyAdmin. Let’s start with the SQL statement. To display the size of a particular MySQL database in MegaByte (MB), use the following SQL command:

SELECT table_schema,
sum( data_length + index_length ) / 1024 / 1024 "Database Size in MB"
FROM information_schema.TABLES WHERE table_schema="{my_database_name}" GROUP BY table_schema

However, within the statement, before the execution, the placeholder {my_database_name} must be replaced by the name of the database whose size is to be determined. If the size of all database should be displayed on the MySQL server, the where clause can be omitted. […]