haglandgarcia -- bash
> Initializing network stack[OK]
> DNS resolver check[ACTIVE]
> Active Directory schema[LOADED]
> Kerberos KDC reachable[OK]
> Firewall ruleset v4.2.1[ARMED]
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Real-world guides on Active Directory, DNS, Firewalls, Kerberos, and more, written by engineers who live it daily.

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~/articles/understanding-kerberos-aut..
Understanding Kerberos Authentication in Active Directory
Active Directory

Understanding Kerberos Authentication in Active Directory

Kerberos is the backbone of authentication in every Windows domain. Understanding how it works and how it fails is essential knowledge for any AD administrator.

A
ADRIAN·29 June 2026
READ
~/articles/troubleshooting-dns-failur..
$ nslookup haglandgarcia.com
Server: 192.168.1.1
Non-authoritative answer:
Name: haglandgarcia.com
Address: 172.67.152.192
DNS

Troubleshooting DNS Failures in Windows Environments

DNS failures are one of the most common causes of network outages. This guide walks through a systematic approach to diagnosing and fixing DNS issues in Windows.

R
ROY·29 June 2026
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~/videos/step-by-step-guide-kerbe..▶ VIDEO
Step by step guide: Kerberos Hardening (KB5073381)
Kerberos

Step by step guide: Kerberos Hardening (KB5073381)

Part I: What is Kerberos and how to face RC4 deprecation - Theorical Lesson Part II: msDS-SupportedEncryptionTypes and etypes: How to calculate Kerberos Encryption Types Part III: RC4DefaultDisablementPhase - How to Identify Accounts Affected by Kerberos Hardening Part IV: 3 Quick Fixes to Stay Safe from Kerberos 2026 Hardening

A
ADRIAN
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Meet the Authors

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Roy Hagland

Networking

Roy is a networking specialist with expertise in DNS, firewalls, routing and network security.

A

Adrian Garcia

Active Directory

Adrian is an Active Directory specialist covering AD DS, GPO, Kerberos authentication, PKI and identity management.