Articles by author: Stefan

Upgrading memory on my XCP-NG hypervisor servers from 32Gb RAM to 64Gb RAM

The blog post shows a Python script which can look up an Asset tag in Snipe-IT with a generated QR code

Creating QR code for wireless networks and a MeCard with Linux

Official Cert Guide Cisco Certified DevNet Associate DEV ASC 200-901 book available and arrived from the USA to Germany.

Some thoughts after the Cisco DevNet Create Live Event

Learning material for network automation with books, videos, podcasts, courses and API, libraries and tools

Installing Gitlab on Debian Linux and connecting with Atom editor

After an upgrade to the new released version 2.9.0 of NetBox the Login failed with Server Error (Missing required package/WSGI service not restarted after upgrade)

Python scripts with API calls as Custom Links for Snipe-IT and LibreNMS.

Today DEF CON 28 is starting in Safe Mode with Networking

Integration of Snipe-IT Asset Management into Netbox DCIM/IPAM as Custom Link with a PHP script and using Snipe-IT API call.

Moving my website to Pelican (Static Site Generator) with introduction to my toolchain, tricks for development, pelican-plugins used on my website and design changes and other improvements

Screenshots of XCP-NG Upgrade to 8.1

Upgrading XCP-NG Hypervisor from version 7.6 to 8.1 remotely over VPN connection and KVM. Fixing IPTables and SNMP configuration for monitoring system.

This is the third part of a series of blog posts covering my new netbox installation. This part shows how to integrate NAPALM and Graphs on device Interfaces from the Monitoring system LibreNMS.

This is the second part of a series of blog posts covering my new netbox installation. The rack is filled up with the rest of the hardware and each network port is getting cabled. This part contains also IPAM (IP Address Management) and handling of Provider and Circuits.

Screenshots of Netbox 2.8.5 installation

This is the first part of a series of blog posts covering my new netbox installation. It covers the defining of manufacturers, device types, power panels and power feeds. An UPS, Power Strips and two Cisco switches are added including their Power cabling. As bonus, the Cisco switches are build as Virtual Chassis (Cisco Switch-stack).

Cisco CleanAir quality report for 2.4GHz WiFi in my area

Useful Cisco Commands for Troubleshooting problematic cabling (Cat.x and Fiber optics).

Simple High Availability with CARP (Common Address Redundancy Protocol)

Cisco Live 2020 Barcelona, Day #5 - SD-WAN, deployment strategies, managing and monitoring

Cisco Live 2020 Barcelona, Day #4 - Catalyst 9000 Access Switching Architecture and Resolving Network Faults Faster through Automating Entire Fault Management

Cisco Live 2020 Barcelona, Day #3 - About Garlic and Onions and Industrial automation

Cisco Live 2020 Barcelona, Day #2 - Attack Kill Chain and Packet Capturing

Cisco Live 2020 Barcelona, Day #1 - A cat and mouse Game

Simple load balancing with Apache proxy_balancer and testing with siege

Replacing faulty memory for Cisco ASA-5520, checking memory and failover

Princeton University and University of Chicago published a study of the tracking Ecosystem of Over-the-Top TV Streaming Devices

Humblebundle.com has a nice books bundle of Linux + Unix books by O'Reilly. And a tipp for the best Currywurst: Bruzzelhütte, Hamburg

NetBox, Snipe-It and LibreNMS: Three tools for Data Center Information Management (DCIM), IT Asset Management (ITAM) and Network Monitoring System (NMS).

Cisco ASA5520 stuck at Booting system, please wait... and how to check for faulty memory

Bookmarks and links to Security and security research related web sites

Bookmarks and links to various other blogs and websites

Bookmarks and links to various Podcasts and Video channels

The procedure how to convert a Cisco lightweight AP to a standalone AP

Humblebundle.com has a nice books bundle of IT Security books, available as PDF and as EPUB, DRM-free

Cisco Unified IP Phone 7975G with Sipgate, from configuring switches, setting up DHCP and TFTP, and do the correct SEPMAC.cnf.xml file configuration and firewall ACL.

Building a High-Availability cluster with XCP-NG

Bookmarks and links to Free and open source software web sites

Alienware laptop hardware replacement

Pictures of my Alienware A51 Laptops

Connecting to Cisco console with Linux

Bookmarks and links to various RSS feeds

Testing Panduit CBOT24K cabling organizer

Creating ROOT-CA-based certificates for Cisco Wireless Controller

Creating ROOT-CA-based certificates for Synology Diskstation

Blocking Facebooks networks on ASA firewall

35C3 and braindump about blocking of facebooks network range

Liste der Datenschutzbehoerden in Deutschland

How to securely put your boarding pass on the internet

Oh no, snow

Schnitzel Day (with Wiener Schnitzel) in Germany

Setting up Cisco 3504 series wireless controller redundancy

Bilder meiner Reise nach Hamburg Germany im August 2018

In Germany... Hacker-Conference comes to you

Setting up administrative RADIUS logins on AIR-AP2800 with Mobility Express

WiFicalypse continued, new method to speed up cracking of WPAv1 / WPAv2 Pre-sharded keys

A Trick to activate CLI Commands on Cisco Lightweight AP

Some impressions of the lunar eclipse 2018 over Germany

saveconfig, two scripts to backup configuration files from network devices

Optimierungen und Static Site Generator, Automatisierung für meine Website

The Cisco hardware I have at home

A simple bash script to create ASA Firewall rules from Talos IP Blacklist

Anmerkungen zum Independence Day und Website Updates mit Volltext-Suche

Ältere Bilder meiner Modelleisenbahn (Lokomotiven und Wagen)

Bilder meiner Reise nach Metepec, Mexico im April und Mai 2018, Metepec Downtown, Los Foquitos

Added GDPR - General Data Protection Regulation / DSGVO - Datenschutzgrundverordnung

Icebound. Too much snow and ice for me.

Travel to Germany, returned with some fun stuff

WiFicalypse Update with vendor lists, press statements

WiFicalypse, KrackAttack to break WPA version 2

WiFi Spectrum Analysis with Cisco 3600 Series AP and Outdoor antenna

Websites updates, my old website thierolf.org is back online, yeah!

Mein privates Cisco Lab mit Switches, Firewall, Routers, WiFi Controller

Changing Rsyslog's default template for a MariaDB database

Bilder der Solar Eclipse 2017 aus New Hampshire, USA

Solar Eclipse 2017, Impressionen der Sonnenfinsternis aus New Hampshire, USA

Cyber-Feuerwehr and Cyber-System failure

A quick overview of the 802.11 standards for Wireless networks

Theme and website updates and ticket for 34C3

Website updates and SHA2017 videos on CCC media server

CSAchecker, a Cisco Security Advisory checker

Short instructions how to convert a Cisco 2600 Series Access Point

Overview of common Cisco switch port errors and causes

Bilder meiner Reise nach Metepec, Mexico im April 2017, Metepec Downtown und der Hill of the Magueyes

Travel to Mexico: Photos of my trip from Metepec downtown

Verschiedene Bilder aus den USA

How to secure the Cisco console with AAA

Snow snow snow: After Winter Storm Orson

New Cisco switch for my network: WS-C3750G-24TS-S1U

How to move SSH port on Cisco devices to another port than TCP/22

Playing Elite:Dangerous - Welcome KEY-LOH-OSS-CAH-NO-VEM-BER.

Updated links and new Alienware laptop after my return flight to the US

How to setup Postfix as satellite System (smarthost)

Bilder meines Alienware 17 Laptops

Website update mit Flex Box, Motto: Vom Hirn ins Terminal seit 1998.

Spass mit der Console: Cowsay fortunes mit lolcat unter Debian Jessie

Sicherer Mail server fertig, mit Crypto und so

Neue Website online (Mal wieder richtige Website anstelle einer Mail-Info)

The Cisco hardware I have at home

Bilder meiner Reise nach Wuxi China und Pattaya Thailand im September 2015

Bilder meiner Reise nach Queretaro Mexico im November 2014

Travel to Old Sarum, England in 2012

Travel to Stonehenge, England in 2012

Travel to Woodhenge, England in 2012

Travel to Berlin, Pergamon Museum in 2012

Bilder meiner Reise nach New Dehli, India in 2012

Bilder meiner Reise nach Sao Paulo, Brasilien im November 2011, Sao Paulo Downtown

Bilder meiner Reise nach England im August 2010, Dover harbour

Roman castle, Richborough England, 2010