Category: Debian

Debian: Postfix + DMARC

Debian-11-postifx

OpenDMARC is an open source implementation of the Domain-based Message Authentication, Reporting and Conformance (DMARC) specification.

DMARC is a policy for mail transfer, which is already supported by some common mail providers. It depends on Sender Policy Framework and DKIM. DMARC provides a policy for outgoing mail and checks incoming mails for compliance with that …

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Debian: Postfix + PostGrey

Debian-11-postifx

Postgrey is a Postfix policy server implementing greylisting. When a request for delivery of a mail is received by Postfix via SMTP, the triplet CLIENT_IP / SENDER / RECIPIENT is built. If it is the first time that this triplet is seen, or if the triplet was first seen, less than 5 minutes ago, then …

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Debian: PuppetServer Cluster

Debian-11-puppet

Puppet is the most powerful configuration management tool in the solar system. It’s the engine that drives your compliance, baseline, drift remediation, and deployment needs. It has always been and always will be open source, with freely downloadable operating system-specific agent packages, a massively scalable server, and data warehousing capabilities via PuppetDB.

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Debian: MariaDB + SSL

MariaDB Server is one of the most popular open source relational databases. It’s made by the original developers of MySQL and guaranteed to stay open source. It is part of most cloud offerings and the default in most Linux distributions.

It is built upon the values of performance, stability, and openness, and MariaDB Foundation ensures …

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Debian: Squid Proxy Server

Squid is a caching proxy for the Web supporting HTTP, HTTPS, FTP, and more. It reduces bandwidth and improves response times by caching and reusing frequently-requested web pages. Squid has extensive access controls and makes a great server accelerator. It runs on most available operating systems, including Windows and is licensed under the GNU GPL.

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Debian: unattended-upgrades + needrestart

Debian 11

The purpose of unattended-upgrades is to keep the computer current with the latest security (and other) updates automatically.

If you plan to use it, you should have some means to monitor your systems, such as installing the apt-listchanges package and configuring it to send you emails about updates. And there is always …

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Debian: apt-cacher-ng

Debian 11

A caching proxy. Specialized for package files from Linux distributors, primarily for Debian (and Debian based) distributions but not limited to those.

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Debian: fail2ban + nftables

Debian-11-fail2ban

Fail2ban scans log files and bans IPs that show the malicious signs — too many password failures, seeking for exploits, etc. Generally Fail2Ban is then used to update firewall rules to reject the IP addresses for a specified amount of time, although any arbitrary other action (e.g. sending an email) could also be configured. Out …

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Debian: Apache + RemoteIP

Debian 11

Often or not someone may place a web farm behind a loadbalancer and not get appropriate remote ip address logging information on the Apache log files. Following entry will describe how to configure Apache to log with the X-Forwarder-For HTTP-Header.

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Debian: Apache + Mod-Security + fail2ban

Debian 11

ModSecurity was originally designed for Apache web server. It could work with Nginx before version 3.0 but suffered from poor performance. ModSecurity 3.0 (aka libmodsecurity) was released in 2017. It’s a milestone release, particularly for Nginx users, as it’s the first version to work natively with Nginx. The caveat of ModSecurity 3 is that it …

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