How to install and use TCPdump on CentOS 7 / 8

TCPdump is a network analyzer utility that can monitor and log, TCP/IP traffic passing through the network and the device from which it is executed. TCPdump is open-source and it’s freely available under the BSD license. it is a command-line interface application and it can provide information about packets in several formats depending on the arguments used.
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How to Secure SSH on CentOS 8 and 7

SSH (also referred to as Secure Shell) is a protocol for remote login to a system securely. SSH provides several alternative options for strong authentication, and it protects the communications from both ends with strong encryptions. SSH is a secure alternative to non-protected protocols such as telnet or rlogin, and it also can provide file transfer services more securely than other common protocols.

In this article, we are not going to talk about obvious things such as “choosing strong passwords” etc. the more technical security hardening methods is the point of this tutorial.
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