How to analyze Squid logs with SARG log analyzer on CentOS

In a previous tutorial, we show how to configure a transparent proxy with Squid on CentOS. Squid provides many useful features, but analyzing a raw Squid log file is not straightfoward. For example, how could you analyze the time stamps and the number of hits in the following Squid log? 1404788984.429 1162 172.17.1.23 TCP_MISS/302 436 […]
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How to set up Squid as a transparent web proxy on CentOS or RHEL

In a previous tutorial, we have seen the method of creating a gateway using iptables. This tutorial will focus on turning the gateway into a transparent proxy server. A proxy is called “transparent” when clients are not aware that their requests are processed through the proxy. There are several benefits of using a transparent proxy. […]
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How to set up a secure FTP service with vsftpd on Linux

FTP or File Transfer Protocol is one of the widely used services on the Internet, mainly for transferring files from one host to other. FTP itself was not designed as a secure protocol, and as such, the classic FTP service is vulnerable to common attacks such as man in the middle and brute force attacks. […]
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How to use LVM in Linux

Logical Volume Manager (LVM) is a versatile disk management system that can easily be used in Linux or similar operating systems. Traditional partitions are created in fixed sizes, and resizing them is a tedious process. On the other hand, LVM creates and manages “logical” volumes off of physical hard disks, and provides administrators the flexibility […]
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How to set up a primary DNS server using CentOS

Any operational domain has at least two DNS servers, one being called a primary name server (ns1), and the other a secondary name server (ns2). These servers are typically operated for DNS failover: If one server goes down, the other server becomes an active DNS server. More sophisticated failover mechanisms involving load balancers, firewalls and […]
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How to set up HTTPS in Apache web Server on CentOS

Web servers use HTTP by default, which is a clear text protocol. As the name suggests, a clear text protocol does not apply any form of encryption on the transit data. While the HTTP-based web server is very easy to set up, it has a major drawback in terms of security. Any “man-in-the-middle” is able […]
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How to set up Nagios Remote Plugin Executor (NRPE) in Linux

As far as network management is concerned, Nagios is one of the most powerful tools. Nagios can monitor the reachability of remote hosts, as well as the state of services running on them. However, what if we want to monitor something other than network services for a remote host? For example, we may want to […]
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