nu11secur1ty nu11secur1ty

Installing ELK (CentOS (6 - NOTE: with your own modified) ,7)

Introduction

In this tutorial, we will go over the installation of the Elasticsearch ELK Stack on CentOS 7—that is, Elasticsearch 2.1.x, Logstash 2.1.x, and Kibana 4.3.x. We will also show you how to configure it to gather and visualize the syslogs of your systems in a centralized location, using Filebeat 1.0.x. Logstash is an open source tool for collecting, parsing, and storing logs for future use. Kibana is a web interface that can be used to search and view the logs that Logstash has indexed. Both of these tools are based on Elasticsearch, which is used for storing logs.

Centralized logging can be very useful when attempting to identify problems with your servers or applications, as it allows you to search through all of your logs in a single place. It is also useful because it allows you to identify issues that span multiple servers by correlating their logs during a specific time frame.

It is possible to use Logstash to gather logs of al

Warning:

The use of direct cable connections without network switches is not supported for bonding. 
The failover mechanisms described here will not work as expected without the presence of network switches. 
See the Red Hat Knowledgebase article Why is bonding in not supported with direct connection using crossover cables? for more information.

Note:

The active-backup, balance-tlb and balance-alb modes do not require any specific configuration of the switch. 
Other bonding modes require configuring the switch to aggregate the links.

EPEL Repository on CentOS 6.5

Extra Packages for Enterprise Linux (EPEL)

#References:

https://fedoraproject.org/wiki/EPEL
http://www.shellhacks.com/en/Adding-EPEL-Repository-on-CentOS-RHEL
https://fedoraproject.org/keys

Environment

Red Hat Enterprise Linux 7 Issue

How to set up yum repository to use locally-mounted DVD with Red Hat Enterprise Linux (RHEL) 7
Would like to upgrade server from RHEL 7.x to RHEL 7.y
Have a secure environment that will never be connected to the internet, but still needs to be updated
Way to update the packages on server, with no satellite server and servers disconnected from internet

##Add remote host to Nagios server

###On Remote Host ####Pre-requisite #####Below listed package should be installed i.gcc ii. xinetd iii.openssl

#####Step 1

Overview

The following is an extremely simplified view of how SSL is implemented and what part the certificate plays in the entire process.

Normal web traffic is sent unencrypted over the Internet. That is, anyone with access to the right tools can snoop all of that traffic. Obviously, this can lead to problems, especially where security and privacy is necessary, such as in credit card data and bank transactions. The Secure Socket Layer is used to encrypt the data stream between the web server and the web client (the browser).

SSL makes use of what is known as asymmetric cryptography, commonly referred to as public key cryptography (PKI). With public key cryptography, two keys are created, one public, one private. Anything encrypted with either key can only be decrypted with its corresponding key. Thus if a message or data stream were encrypted with the server's private key, it can be decrypted only using its corresponding public key, ensuring that the data only could have come from the serve

Linux Runlevels Explained

A runlevel is one of the modes that a Unix -based operating system will run in. Each runlevel has a certain number of services stopped or started, giving the user control over the behavior of the machine. Conventionally, seven runlevels exist, numbered from zero to six.

After the Linux kernel has booted, the init program reads the /etc/inittab file to determine the behavior for each runlevel. Unless the user specifies another value as a kernel boot parameter, the system will attempt to enter (start) the default runlevel. Standard run levels for Red Hat based distributions Run Level Mode Action

0 Halt Shuts down system

	## Configure eth0
	#
	# vi /etc/sysconfig/network-scripts/ifcfg-eth0

	DEVICE="eth0"
	NM_CONTROLLED="yes"
	ONBOOT=yes
	HWADDR=A4:BA:DB:37:F1:04
	TYPE=Ethernet
	BOOTPROTO=static

	#!/bin/bash
	######################################
	# copyright@nu11secur1ty #
	######################################

	# Stop iptables
	/etc/init.d/iptables stop
	yum install wget
	cd ~
	# you can change if you want!

	sudo apt-get install unzip;
	wget -O /tmp/chromedriver.zip http://chromedriver.googlecode.com/files/chromedriver_linux64_19.0.1068.0.zip && sudo unzip /tmp/chromedriver.zip chromedriver -d /usr/local/bin/;