November 2020 - Page 62 of 66

How Fail2Ban Works to Protect Services on a Linux Server — step-by-step Linux tutorial on Progressive Robot

How Fail2Ban Works to Protect Services on a Linux Server

Fail2ban is a daemon that can be used to monitor the logs of services and ban clients that repeatedly fail authentication checks. It is a great tool to help protect against brute force attacks and malicious users. In this guide, we’ll discuss how fail2ban works and how you can leverage its configuration structure to modify or extend its functionality.

Read more
How to generate XSD from Java Class — step-by-step Programming tutorial on Progressive Robot

How to generate XSD from Java Class

In last few posts, we learned about [Java JAXB](/community/tutorials/jaxb-example-tutorial "JAXB Example Tutorial") and how to generate [java class from XSD](/community/tutorials/jaxb2-maven-plugin-xjc-example-generate-java-classes-xsd "How to Generate Java Classes from XSD using XJC Maven Plugin"). Today we will learn how to generate XSD from java classes. Generate XSD from Java Class ![generate xsd from java, xsd generator, java class […]

Read more
Debian 10 — kconfig — vulnerability — patch and remediation guide — diagnosis and fix on Debian 10

Debian 10 — kconfig — vulnerability — patch and remediation guide

🟢 Low   ⏱ 5–15 min  Last verified: 25 May 2026 Affected versions: Debian 10 (buster) 📖 ~4 min read  •  Source: Debian Security Tracker Related CVEs: CVE-2019-14744 Table of contents Symptom & Impact Environment & Reproduction Root Cause Analysis Quick Triage Step-by-Step Diagnosis Solution – Primary Fix Solution – Alternative Approaches Verification & Acceptance […]

Read more
How to Configure Logrotate on FreeBSD 12 — step-by-step FreeBSD 12 tutorial on Progressive Robot

How to Configure Logrotate on FreeBSD 12

Introduction How to Configure Logrotate on FreeBSD 12 is a core administration task for any FreeBSD 12 server operator. FreeBSD 12 ships with the 15.0-RELEASE kernel, ZFS as the default root filesystem, Capsicum capability sandboxing improvements, and an updated ports tree. Unlike Linux distributions, FreeBSD uses rc(8) for service management, pf for packet filtering, and […]

Read more
Oracle Linux 8 — gnutls and nettle security, bug fix, and — enhancement update — new behaviour and fixes — diagnosis and fix on Oracle Linux 8

Oracle Linux 8 — gnutls and nettle security, bug fix, and — enhancement update — new behaviour and fixes (ELSA-2021-4451)

🟡 Medium   ⏱ 10–30 min  Last verified: 25 May 2026 Affected versions: Oracle Linux 8 📖 ~4 min read  •  Source: ELSA advisory ELSA-2021-4451 Related CVEs: CVE-2021-20232 CVE-2021-3580 CVE-2021-20231 Table of contents Symptom & Impact Environment & Reproduction Root Cause Analysis Quick Triage Step-by-Step Diagnosis Solution – Primary Fix Solution – Alternative Approaches Verification […]

Read more
FreeBSD 12 — py36-twisted — multiple vulnerabilities (6 CVEs) — patch and remediation guide — diagnosis and fix on FreeBSD 12

FreeBSD 12 — py36-twisted — multiple vulnerabilities (6 CVEs) — patch and remediation guide

🟡 Medium   ⏱ 10–30 min  Last verified: 25 May 2026 Affected versions: FreeBSD 12 📖 ~4 min read  •  Source: FreeBSD VuXML VuXML topic: py-twisted — multiple vulnerabilities Related CVEs: CVE-2019-12387 CVE-2019-9512 CVE-2019-9514 CVE-2019-9515 CVE-2020-10108 CVE-2020-10109 Upstream summary: Twisted developers reports: All HTTP clients in twisted.web.client now raise a ValueError when called with a […]

Read more
Common Problems 118504

Ubuntu 16.04 LTS netplan not present causes confusion with interface config

🟢 Low   ⏱ 5–30 min  Last verified: 19 May 2026 Affected versions: 16.04 📖 ~1 min read Table of contents Symptom & Impact Environment & Reproduction Root Cause Analysis Quick Triage Step-by-Step Diagnosis Solution – Primary Fix Solution – Alternative Approaches Verification & Acceptance Criteria Rollback Plan Prevention & Hardening Related Errors & Cross-Refs […]

Read more
CHAT