How to set up IPv6 BGP peering and filtering in Quagga BGP router

In the previous tutorials, we demonstrated how we can set up a full-fledged BGP router and configure prefix filtering with Quagga. In this tutorial, we are going to show you how we can set up IPv6 BGP peering and advertise IPv6 prefixes through BGP. We will also demonstrate how we can filter IPv6 prefixes advertised […]
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How to make remote incremental backup of LUKS-encrypted disk/partition

Some of us have our hard drives at home or on a VPS encrypted by Linux Unified Key Setup (LUKS) for security reasons, and these drives can quickly grow to tens or hundreds of GBs in size. So while we enjoy the security of our LUKS device, we may start to think about a possible […]
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How to analyze and view Apache web server logs interactively on Linux

Whether you are in the web hosting business, or run a few web sites on a VPS yourself, chances are you want to display visitor statistics such as top visitors, requested files (dynamic or static), used bandwidth, client browsers, and referring sites, and so forth. GoAccess is a command-line log analyzer and interactive viewer for […]
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How to filter BGP routes in Quagga BGP router

In the previous tutorial, we demonstrated how to turn a CentOS box into a BGP router using Quagga. We also covered basic BGP peering and prefix exchange setup. In this tutorial, we will focus on how we can control incoming and outgoing BGP prefixes by using prefix-list and route-map. As described in earlier tutorials, BGP […]
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What are useful command-line network monitors on Linux

Network monitoring is a critical IT function for businesses of all sizes. The goal of network monitoring can vary. For example, the monitoring activity can be part of long-term network provisioning, security protection, performance troubleshooting, network usage accounting, and so on. Depending on its goal, network monitoring is done in many different ways, such as […]
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How to deduplicate files on Linux with dupeGuru

Recently, I was given the task to clean up my father’s files and folders. What made it difficult was the abnormal amount of duplicate files with incorrect names. By keeping a backup on an external drive, simultaneously editing multiple versions of the same file, or even changing the directory structure, the same file can get […]
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How to set up a cross-platform backup server on Linux with BackupPC

Just in case you haven’t been able to tell from my earlier posts on backupninja and backup-manager, I am a big backup fan. When it comes to backup, I’d rather have too much than not enough, because if the need arises, you will be grateful that you took the time and effort to generate extra […]
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How to configure fail2ban to protect Apache HTTP server

An Apache HTTP server in production environments can be under attack in various different ways. Attackers may attempt to gain access to unauthorized or forbidden directories by using brute-force attacks or executing evil scripts. Some malicious bots may scan your websites for any security vulnerability, or collect email addresses or web forms to send spams […]
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How to block unwanted IP addresses on Linux efficiently

You may want to block IP addresses on your Linux box under various circumstances. For example, as an end user you may want to protect yourself from known spyware or tracker IP addresses. Or when you are running P2P software, you may want to filter out connections from networks associated with anti-P2P activity. If you […]
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How to configure rsyslog client for remote logging on CentOS

rsyslog is an open source utility widely used on Linux systems to forward or receive log messages via TCP/UDP protocols. rsyslog daemon can be configured in two scenarios. Configured as a log collector server, rsyslog daemon can gather log data from all other hosts in the network, which are configured to send their internal logs […]
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