Articles by author: Stefan
Add Virtual Machine to NetBox with an Ansible playbook
In this blog post I'm showing how to get a Virtual Machine, defined in an Ansible inventory file, into the NetBox DCIM (Data Center Information Management) tool.
NetFlow with Elastic-Stack
This blog post shows how to setup a NetFlow collector with Elastic-Stack, Fleet and Elastic-Agent. NetFlow data is sent by a Cisco ASA Firewall cluster.
Technischer Schutz und Prozesse bei Datenlecks
In diesem Blog-Post beschreibe ich meine technischen Schutzmaßnahmen (Email) und Prozesse, wenn ich von einem Datenleck betroffen bin.
odenwald.social
Just a quick announcement: Die Mastodon-Instanz odenwald.social ist freigeschaltet. Viel Spass ;)
Cisco Wireless Intrusion Detection Events to Elastic-Stack
In this blog post I'm showing how to get Wireless Intrusion Detection Events from Cisco's WIDS included in Cisco's Wireless Controllers into an Elastic-Stack.
802.1X Switch port is amber when only IP Phone is connected
When 802.1X (wired) is configured on a 3750G switch, the port LED is amber when only an IP Phone is connected (mab). When connecting on the IP Phone a downstream device like a laptop (dot1x), the port LED goes to green.
Login-Block (DoS and Dict-Attack Protection) in Cisco IOS
Cisco offers a method to protect against DoS (Denial-of-Service) and Dictionary attacks for IOS devices called Login-Block.
Update Schneider-APCUPS firmware with Linux
In this blog post I'm showing how to update a Schneider-APC UPS with Linux.
Mapping of IP addresses blocked by Russia
Mapping of IP addresses blocked by Russia
Werbeemails aufgrund LinkedIn Profils
Werbeemails aufgrund LinkedIn Profils / SPAM mails due to LinkedIn Profile.
Tor project / Tor bridge
Tor project / Tor bridge.
New fiber optics cables for my network
New fiber optics cables for my network. OM4, LC/LC connectors, 4x1 Gigabit link.
The 90’s reported in and delivered a phone book
The 90's reported in and delivered a phone book.
Synology DiskStation to Cisco Core Switch redundant setup with LACP
Configuration of LCAP (Link Aggregation Control Protocol) for Synology DiskStation and Cisco Switch.
Schneider-APCUPS battery replacement
Small how-to about Schneider-APC UPS battery replacement and setting replacement date in Network management card.
Elastic-Stack for network engineers (Initial setup)
Switching from traditional log monitoring to Elastic-Stack is like switching from a horse-drawn carriage to the Falcon 9 rocket. Join the journey!
Cisco SSM On-Prem Upgrade procedure
This is another blog post for Cisco SSM On-Prem server where I'm showing the upgrade process.
Cisco ISE admin password lifecycle and reset
Quick notes about Cisco Identity Services Engine password lifetime and admin password reset.
Cisco SSM On-Prem password recovery procedure
For a Cisco Smart Software Manager Test Drive installation I used the older version 8-202010 and I wanted to perform an upgrade to the latest version 8-202108. And of course it is a test drive, I did not save or wrote down the password :). In this document I'm describing how to perform a password recovery for a Cisco SSM On-Prem installation.
Upgrading Netbox to Version 3.0
Yesterday, the version v3.0 of Netbox was released. Modernized WebUI and Off-canvas sidebar. My first impression: Version v3.0 is awesome! Note: Version v3.0.1 was released on 2021-09-01.
Gitlab AD-LDAP Integration
In this blog post I'm showing how to integrate GitLab Server with a Samba-based Active Directory.
Troubleshooting SFP transceivers and Packet captures
In an older blog post I was writing about "Useful Cisco Commands for Troubleshooting cable problems". In this blog post I'm showing an additional, useful command for Fiber Optics troubleshooting and packet capturing on Cisco switches.
SiSyPHuS Win 10 Telemetry blocklist for Pi-Hole
Based on the latest SiSyPHuS Analysis of BSI I built a small blocklist for Pi-Hole to drop Win 10 Telemetry data collection
Cisco WLC - No secured WebUI after failover switching
Cisco WLC 3504 secured WebUI is not working on Secondary Unit in a failover (SSO) setup. When switched back to the Primary Unit, the secured WebUI is working again. Troubleshooting and solution of this strange behavior.
Some security settings for Apache Web Server
I'm showing in this blog post some security settings for the Apache web server including disabling of Directory Browsing, Server Signature and Server Token.
Integration of Nextbox UI Topology Viewer in Netbox
In this blog post I'm showing how to integrate NextBox UI Plugin into my Netbox installation. NextBox UI Plugin is a topology visualization plugin which is based on Cisco's neXt toolkit.
City of Erbach is ending their partnership with Odenwald gegen rechts
City of Erbach is ending their partnership with "Odenwald gegen rechts" ("Odenwald against Right")
WiFicalypse 2021
WiFicalypse 2021, FragAttacks. Design and Implementation flaws in WiFi.
Small Python script to quick test DMARCDKIM and SPF records
For a given occasion I wrote Small Python script to test a domain for DMARC, DKIM and SPF records. Those records are managed in a DNS Zone and are typically used in Anti-SPAM techniques.
Netbox Active Directory/LDAP Integration
In my newest blog post I show how to setup Netbox with Active Directory as backend for users and groups.
Concept for DNS security with Bind9, Pi-hole and OpenDNS
This is my new concept for DNS security with Bind9, Pi-hole and OpenDNS in my network. Bind9 is used as Enterprise DNS to resolve hostnames and IP addresses in the local area network, Pi-hole and OpenDNS are used for Internet DNS traffic. DNS traffic is passed by Cisco ASA Firewall ACL.
Album: Pi-hole installation on Debian Linux
Screenshots of Pi-hole installation on Debian Linux
Humble Book Bundle - The Ultimate Python Bookshelf by Packt
Humble Book Bundle - The Ultimate Python Bookshelf by Packt including Data Analysis, Artificial Intelligence, Machine Learning, Django, Automation
Blocking of Google Chrome FLoC
Blocking of Google Chrome FLoC (Federated Learning of Cohorts) on my web server
Weeks of the data leaks
Weeks of the data leaks and my approach after data leaks or breaches
Debian Unattended upgrades
Automatically install security-related upgrades on Debian Linux with unattended-upgrades
Most useful tip from Cisco Live 2021
Most useful tip from Cisco Live 2021 and it's implementation
Fritzbox rack mounted
Fritzbox rack mounted on a 19" shelf and it's hardware issues: white description on a white box, no LED on ports for activity, height unit issues, Square wood and Velcro to fix ;)
Check in of configuration files to a Gitlab server
This is the third part of a series of blog posts about Cisco configuration backup with Netbox and Gitlab. This blog post covers the check in of configuration files to a Gitlab server
Low Level Device functions for backup with Netbox and Gitlab
This is the second part of a series of blog posts about Cisco configuration backup with Netbox and Gitlab. This blog post covers the low level functions to connect to network devices with pexpect.
Cisco configuration backup with Netbox and Gitlab
This is the first part of a series of blog posts about Cisco configuration backup with Netbox and Gitlab. It covers the connection to the Netbox API and to get the data of network devices with the pynetbox filter function.
In case of fire
In case of fire: Leave the building before posting it on social media
Fritzbox on redundant ASA Firewall
Setup of two redundant Cisco ASA firewalls on a Fritzbox cable modem with Non-routed transfer network to keep the "PC-MAC"/"exposed host" configuration on Fritzbox during ASA failover switching
Cisco Smart Software Manager Test Drive
Cisco Smart Software Manager (SSM) On-Prem Test Drive installation, Virtual Machine setup and first steps in the Web UI
Humble Book Bundle Programming Fundamentals
Humblebundle.com has a nice books bundle of Programming Fundamentals, available as PDF and as EPUB, DRM-free
Upgrading memory on my XCP-NG hypervisors
Upgrading memory on my XCP-NG hypervisor servers from 32Gb RAM to 64Gb RAM
Looking up asset tags in Snipe-IT with QR code
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
Creating QR code for wireless networks and a MeCard with Linux
Official Cert Guide Cisco Certified DevNet Associate
Official Cert Guide Cisco Certified DevNet Associate DEV ASC 200-901 book available and arrived from the USA to Germany.
Cisco DevNet Create 2020
Some thoughts after the Cisco DevNet Create Live Event
Learning material for network automation
Learning material for network automation with books, videos, podcasts, courses and API, libraries and tools
Installing Gitlab on Debian Linux
Installing Gitlab on Debian Linux and connecting with Atom editor
Netbox Login failed after upgrade to version 2.9.0
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)
Netbox Custom Links for Snipe-IT and LibreNMS
Python scripts with API calls as Custom Links for Snipe-IT and LibreNMS.
DEFCON 28 - Safe Mode with Networking
Today DEF CON 28 is starting in Safe Mode with Networking
Custom links in Netbox for Snipe-IT Asset Management
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)
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
Album: XCP-NG Upgrade to 8.1
Screenshots of XCP-NG Upgrade to 8.1
Upgrading XCP-NG Hypervisor from version 7.6 to version 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.
Netbox: New installation (2.8.5) and NAPALM plus LibreNMS API integration
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.
Netbox: New installation (2.8.5) and cabling and assigning IP addresses
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.
Album: Netbox 2.8.5 installation
Screenshots of Netbox 2.8.5 installation
Netbox: New installation (2.8.5) and filling up an empty rack
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).
Why 2.4 GHz WiFi is bad
Cisco CleanAir quality report for 2.4GHz WiFi in my area
Useful Cisco Commands for Troubleshooting cable problems
Useful Cisco Commands for Troubleshooting problematic cabling (Cat.x and Fiber optics).
Simple High Availability with CARP
Simple High Availability with CARP (Common Address Redundancy Protocol)
Cisco Live 2020 Barcelona, Day 5
Cisco Live 2020 Barcelona, Day #5 - SD-WAN, deployment strategies, managing and monitoring
Cisco Live 2020 Barcelona, Day 4
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
Cisco Live 2020 Barcelona, Day #3 - About Garlic and Onions and Industrial automation
Cisco Live 2020 Barcelona, Day 2
Cisco Live 2020 Barcelona, Day #2 - Attack Kill Chain and Packet Capturing
Cisco Live 2020 Barcelona, Day 1
Cisco Live 2020 Barcelona, Day #1 - A cat and mouse Game
Simple load balancing with Apache proxy_balancer
Simple load balancing with Apache proxy_balancer and testing with siege
Replacing faulty memory for Cisco ASA-5520
Replacing faulty memory for Cisco ASA-5520, checking memory and failover
Watching You Watch
Princeton University and University of Chicago published a study of the tracking Ecosystem of Over-the-Top TV Streaming Devices
Humble Book Bundle Linux Unix and Bruzzelhuette Hamburg
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
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…
Cisco ASA5520 stuck at Booting system, please wait... and how to check for faulty memory
Security and Security Research
Bookmarks and links to Security and security research related web sites
Various Blogs and Webites
Bookmarks and links to various other blogs and websites
Various Podcasts
Bookmarks and links to various Podcasts and Video channels
Convert Cisco lightweight AP to standalone AP
The procedure how to convert a Cisco lightweight AP to a standalone AP
Humble Book Bundle IT Security
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
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
Building a High-Availability cluster with XCP-NG
Free and open source software
Bookmarks and links to Free and open source software web sites
Alienware laptop hardware replacement
Alienware laptop hardware replacement
Album: Alienware A51 Laptop
Pictures of my Alienware A51 Laptops
Connecting to Cisco console with Linux
Connecting to Cisco console with Linux
Various RSS-Feeds
Bookmarks and links to various RSS feeds
Testing Panduit CBOT24K cabling organizer
Testing Panduit CBOT24K cabling organizer
Creating ROOT-CA-based certificates for Cisco Wireless Controller
Creating ROOT-CA-based certificates for Cisco Wireless Controller
Creating ROOT-CA-based certificates for Synology Diskstation
Creating ROOT-CA-based certificates for Synology Diskstation
Blocking Facebooks networks on ASA firewall
Blocking Facebooks networks on ASA firewall
35C3 and braindump about blocking of facebooks network ranges
35C3 and braindump about blocking of facebooks network range
Datenschutzbehoerden in Deutschland
Liste der Datenschutzbehoerden in Deutschland
How to securely put your boarding pass on the internet
How to securely put your boarding pass on the internet
Oh no, snow
Oh no, snow
Schnitzel Day (with Wiener Schnitzel)
Schnitzel Day (with Wiener Schnitzel) in Germany
Setting up Cisco 3504 series wireless controller redundancy
Setting up Cisco 3504 series wireless controller redundancy
Album: Travel to Hamburg Germany in 2018
Bilder meiner Reise nach Hamburg Germany im August 2018
In Germany… Hacker-Conference comes to you
In Germany... Hacker-Conference comes to you
Setting up administrative RADIUS logins on AIR-AP2800 with Mobility Express
Setting up administrative RADIUS logins on AIR-AP2800 with Mobility Express
WiFicalypse continued
WiFicalypse continued, new method to speed up cracking of WPAv1 / WPAv2 Pre-sharded keys
Activate CLI Commands on Lightweight AP
A Trick to activate CLI Commands on Cisco Lightweight AP
Lunar Eclipse 2018
Some impressions of the lunar eclipse 2018 over Germany
Saveconfig Backup scripts
saveconfig, two scripts to backup configuration files from network devices
Optimierungen und Static Site Generator
Optimierungen und Static Site Generator, Automatisierung für meine Website
Album: The Cisco hardware I have at home
The Cisco hardware I have at home
Create ASA Firewall rule from Talos IP Blacklist
A simple bash script to create ASA Firewall rules from Talos IP Blacklist
Independence Day und Website Updates
Anmerkungen zum Independence Day und Website Updates mit Volltext-Suche
Bilder Modelleisenbahn
Ältere Bilder meiner Modelleisenbahn (Lokomotiven und Wagen)
Album: Travel to Toluca Mexico in 2018
Bilder meiner Reise nach Metepec, Mexico im April und Mai 2018, Metepec Downtown, Los Foquitos
Added GDPR (DSGVO)
Added GDPR - General Data Protection Regulation / DSGVO - Datenschutzgrundverordnung
Icebound
Icebound. Too much snow and ice for me.
Travel to Germany
Travel to Germany, returned with some fun stuff
WiFicalypse Update
WiFicalypse Update with vendor lists, press statements
WiFicalypse
WiFicalypse, KrackAttack to break WPA version 2
WiFi Spectrum Analysis
WiFi Spectrum Analysis with Cisco 3600 Series AP and Outdoor antenna
Websites updates
Websites updates, my old website thierolf.org is back online, yeah!
Mein privates Cisco Lab
Mein privates Cisco Lab mit Switches, Firewall, Routers, WiFi Controller
Rsyslog with MariaDB template
Changing Rsyslog's default template for a MariaDB database
Album: Solar Eclipse 2017
Bilder der Solar Eclipse 2017 aus New Hampshire, USA
Solar Eclipse 2017 in New Hampshire
Solar Eclipse 2017, Impressionen der Sonnenfinsternis aus New Hampshire, USA
Cyber-Feuerwehr
Cyber-Feuerwehr and Cyber-System failure
Quick overview of the 802.11 standards
A quick overview of the 802.11 standards for Wireless networks
Theme and website updates
Theme and website updates and ticket for 34C3
Website updates and SHA2017
Website updates and SHA2017 videos on CCC media server
CSAchecker
CSAchecker, a Cisco Security Advisory checker
Convert Cisco 2600 Series Access Point
Short instructions how to convert a Cisco 2600 Series Access Point
Common Cisco switch port errors
Overview of common Cisco switch port errors and causes
Album: Travel to Toluca Mexico in 2017
Bilder meiner Reise nach Metepec, Mexico im April 2017, Metepec Downtown und der Hill of the Magueyes
Travel to Mexico
Travel to Mexico: Photos of my trip from Metepec downtown
Album: Verschiedene Bilder aus den USA
Verschiedene Bilder aus den USA
Secure Cisco console with AAA
How to secure the Cisco console with AAA
Snow snow snow
Snow snow snow: After Winter Storm Orson
New Cisco switch for my network
New Cisco switch for my network: WS-C3750G-24TS-S1U
Move SSH port on Cisco devices
How to move SSH port on Cisco devices to another port than TCP/22
Welcome KEY-LOH-OSS-CAH-NO-VEM-BER
Playing Elite:Dangerous - Welcome KEY-LOH-OSS-CAH-NO-VEM-BER.
Updated links and new Alienware laptop
Updated links and new Alienware laptop after my return flight to the US
Setup Postfix satellite System
How to setup Postfix as satellite System (smarthost)
Album: Alienware Laptop
Bilder meines Alienware 17 Laptops
Website update mit Flex Box
Website update mit Flex Box, Motto: Vom Hirn ins Terminal seit 1998.
Cowsay fortunes mit lolcat
Spass mit der Console: Cowsay fortunes mit lolcat unter Debian Jessie
Sicherer Mail server fertig
Sicherer Mail server fertig, mit Crypto und so
Neue Website online
Neue Website online (Mal wieder richtige Website anstelle einer Mail-Info)
Album: Roman watchtower, Odenwald Germany, 2016
The Cisco hardware I have at home
Album: Travel to Wuxi China and Pattaya Thailand in 2015
Bilder meiner Reise nach Wuxi China und Pattaya Thailand im September 2015
Album: Travel to Queretaro Mexico in 2014
Bilder meiner Reise nach Queretaro Mexico im November 2014
Album: Travel to Old Sarum, England in 2012
Travel to Old Sarum, England in 2012
Album: Travel to Stonehenge, England in 2012
Travel to Stonehenge, England in 2012
Album: Travel to Woodhenge, England in 2012
Travel to Woodhenge, England in 2012
Album: Travel to Berlin, Pergamon Museum in 2012
Travel to Berlin, Pergamon Museum in 2012
Album: Travel to new Dehli, India in 2012
Bilder meiner Reise nach New Dehli, India in 2012
Album: Travel to Sao Paulo Brazil in 2011
Bilder meiner Reise nach Sao Paulo, Brasilien im November 2011, Sao Paulo Downtown
Album: Travel to Dover England in 2010
Bilder meiner Reise nach England im August 2010, Dover harbour
Album: Roman castle, Richborough England, 2010
Roman castle, Richborough England, 2010