Protocols

What is ICMP protocol and how does it work?

What is the ICMP?

In the background, numerous protocols ensure that communication and data transmission work in computer networks. As the most prominent representative, the Internet Protocol plays a fundamental role. Without its’ various extensions and additions they would be nowhere near as versatile, as is the case in the current protocol. Thanks to the possibilities offered by ICMP protocol error messages and...

ERR_SSL_PROTOCOL_ERROR: the best solutions

ERR_SSL_PROTOCOL_ERROR: how to fix the Chrome bug

Chrome is the world’s most widely-used internet browser. The application scores points not only when it comes to security and speed, but also with its features such as cross-device synchronization of user data. But errors can occur even when surfing with Google’s wonder weapon. These can lead to the browser crashing or prevent certain pages from being accessed. The error message...

UTF-8: encoding global digital communication

UTF-8: the network standard

UTF-8 is method of Unicode character encoding, which claims to cover all modern languages for data processing. The format has significantly influenced international digital communication. But what exactly does “UTF-8” mean? And what is special about UTF-8 in the Unicode character set? Here you can find out which structure the coding is based on, and which bytes are permitted in the standard...

What does ‘502 bad gateway’ mean?: Explanation and solution

Error 502 Bad Gateway: Where’s the problem?

HTTP status codes emerge when something isn’t running properly on the internet. In this respect, the 502 Bad Gateway error is no exception. But this familiar error message can be particularly tricky: It’s not actually clear where the source of the problem lies. In the chain of gateways along which internet requests run, the error could occur at a number of different points. This article explains...

HTTP error 500: Internal Server Error

HTTP error 500: Where does the problem lie and how to fix it?

Error messages when surfing the net are a nuisance for everyone involved, but especially for those who have to find out what the problem is. The search for a solution can be particularly tedious if the status code message barely provides any information on the source of the error. The HTTP error 500 (“Internal Server Error”) is a collective status code. We give you tips on where errors could have...

550 requested action not taken: possible solutions

SMTP error 550: how to fix “Requested action not taken: mailbox unavailable” and other SMTP 550 error messages

If you want to send a message with your e-mail client and the sending fails, you’ll receive a corresponding error message from the server, including an SMTP status code. For example, the message “550 Requested action not taken: mailbox unavailable” means that the targeted address couldn’t be reached. Since this problem can have various causes, even more possible solutions exist, some of which you...

PHP 5.6 Support

PHP 5.6: Support stops at the end of 2018

Security support for PHP 5.6 ceases at the end of the year. Although developers had already postponed the end date by a year, many website operators still seem to be unprepared. A large number of websites still run on PHP 5.6. From January onwards, these websites will be at risk. However, many are dreading the update. How can you protect your website?

401 error: What can you do about it?

Error 401: Unauthorized – No access to the website

You’re surfing around on the internet, but instead of getting the desired content you only receive an error message: annoying or even downright frustrating. Especially if you don’t exactly know what the status is supposed to mean. How are you expected to solve the problem, if you don’t know what’s causing it? This also goes for the error 401. Here we explain what the error means and what you can...

The OSI model: a reference for standards and protocols

What’s the OSI model?

Those working with network technology are bound to encounter the ISO-OSI model sooner or later. This system subdivides communication between computer systems into seven different layers. Each of these layers is assigned a certain task. With the help of this layer model, subareas of abstract processes are able to be descriptively explained.

MAC address

MAC address (media access control)

Without a MAC address, nothing in a network will work on your device. Just as your postman needs a valid address to reliably deliver the mail, the transmission of data packets in computer networks is only possible with the unique hardware address of the target device. When it comes to a MAC address, at least there is one address available on each network-compatible device. But what is the MAC...