How to Locate Open Ports in Linux

Reading Time: 9 minutes
openports

What is a Port? 

First, let’s define what a port is. According to the IEFT, a port is: 

A logical entity for Internet communication. Ports serve two main purposes:
1. They provide a demultiplexing identifier to separate transport sessions between the same pair of endpoints
2. They may also identify the application protocol and associated service to which processes connect.

Wikipedia.com

In plain English, this simply means that a port is an endpoint through which data flows back and forth between two computers over a network. A computer has 65535 ports available to share information. These port numbers are based on a 16-bit number, which is where we derive the total number of available ports (0 to 65535).

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How to Install an SSL on a Core/Unmanaged Ubuntu Server

Reading Time: 8 minutes

Why do I Need to Install or Reinstall My SSL Certificate?

According to Globalsign;

The Certificate Authority (CA) industry was alerted of compliance implications related to the inclusion of a specific extension (OCSP-signing extended key usage) in CA certificates which has, under certain conditions, unintended compliance and security implications. A number of GlobalSign Issuing CAs have been impacted by this issue. While no key compromise or security incident has taken place, we will be revoking these Issuing CA’s as part of our remediation plan in accordance with the CA/B Forum Baseline Requirements and the GlobalSign CPS. Revoked intermediate certificates can cause errors in the validation of certificates signed by these Intermediate Certificates.

Globalsign.com
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How to Install an SSL on a Core/Unmanaged CentOS Server

Reading Time: 7 minutes

Why do I Need to Install or Reinstall My SSL Certificate?

According to Globalsign

The Certificate Authority (CA) industry was alerted of compliance implications related to the inclusion of a specific extension (OCSP-signing extended key usage) in CA certificates which has, under certain conditions, unintended compliance and security implications. A number of GlobalSign Issuing CAs have been impacted by this issue. While no key compromise or security incident has taken place, we will be revoking these Issuing CA’s as part of our remediation plan in accordance with the CA/B Forum Baseline Requirements and the GlobalSign CPS. Revoked intermediate certificates can cause errors in the validation of certificates signed by these Intermediate Certificates.

GlobalSign.com
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SSL vs TLS

Reading Time: 4 minutes

What is the relationship between an SSL and TLS? Most of us are familiar with SSL (Secure Socket Layer) but not TLS (Transport Layer Security). Both protocols are used to transmit online data securely between two endpoints. SSL is older than TLS, but all SSL certificates can use both SSL and TLS encryption. TLS is the replacement protocol to SSL as TLS is the updated version of the SSL protocol. TLS operates similarly to SSL by using encryption methods to ensure secure communication.

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What is REST API? An Overview

Reading Time: 5 minutes

What is REST?

The REST acronym is defined as a “REpresentational State Transfer” and is designed to take advantage of existing HTTP protocols when used for Web APIs. It is very flexible in that it is not tied to resources or methods and has the ability to handle different calls and data formats. Because REST API is not constrained to an XML format like SOAP, it can return multiple other formats depending on what is needed. If a service adheres to this style, it is considered a “RESTful” application. REST allows components to access and manage functions within another application.

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