Saturday 31 March 2018

How to fix SSH vulnerabilities: HMAC algorithms and CBC Ciphers in CentOS 7

SSH Protocol: Enable protocol version 2: Uncomment Protocol 2 in /etc/ssh/sshd_config as below:

How to fix SSH vulnerabilities: HMAC algorithms and CBC Ciphers in CentOS 6

SSH Protocol: Enable protocol version 2

How to install EPEL repository on Centos7

The EPEL repository is an additional package repository that provides useful software packages that are not included in the official Centos or Red Hat repositories and easy access to install packages for commonly used software.

How to Set Password Policy on CentOS7/RHEL7

Password Policy for user accounts is one of the most important parts in Server Administration. The maximum number of days allowed, minimum number of days allowed, and number of warning days before the password expires refers to password aging, same as the number of characters needed to have for the password to be allowed refers to password length. Centos 7, Red Hat 7 and most of Linux distribution is the ability to manage and implement the password policies. 

How to configure Rsyslog - Client configuration

Install rsyslog package using below command, if not available on the client:

Friday 30 March 2018

How to Disabling all SSL/TLS Protocols except TLSv1.2 in CentOS7/RHEL7

Secure Socket Layer (SSL) and Transport Layer Security (TLS) are both cryptographic protocols providing encrypted and secure communication between servers, clients, machines and applications operating over a network.

Wednesday 21 March 2018

How to join CentOS7/RHEL7 to Active Directory using Winbind

We can integrate a Linux host with Windows Active Directory domain controller for authentication purpose. To complete the scenario, we have Centos / RHEL 7 servers and existing Active Directory domain controller. Also required AD administrator account or user has sufficient rights to join AD.

How to configure NTP Client in Centos7/RHEL7

First, install ntp package on client machine:

How to fix CIFS Error Mount: wrong fs type, bad option, bad superblock while mounting windows share Drive

Not able to mount CIFS share on client getting error "mount: wrong fs type, bad option, bad superblock"

Monday 12 March 2018

The client must use SMB client signing for connecting to samba servers using smbclient

Packet signing can prevent man-in-the-middle attacks which modify SMB packets in transit. SMB Signing is a feature through which communications using SMB can be digitally signed at the packet level. Digitally signing the packets enables the recipient of the packets to confirm their point of origination and their authenticity.

Thursday 8 March 2018

How to print Number of Processing Units - nproc

The nproc command just prints out the number of processing units available. Note that the number of processing units might not always be the same as number of cores.

How to change the SSH Port in Linux distribution

We can change the default SSH port in Linux distribution as an added security concerns.

How to install and use tcpdump command on Centos7/RHEL7

TCPDump is a command line packet sniffer/ packet analyzer tool which used to capture or filter TCP/IP packets that received or transferred over a network on a specific interface.