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Who is WHOIS?
I am using the WHOIS client a lot these days since I am migrating some RIPE objects such as ASes, inetnum/inet6num, etc. Meanwhile, I recognized that I have never captured this TCP port 43 protocol,...
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The Ultimate PCAP
For the last couple of years, I captured many different network and upper-layer protocols and published the pcaps along with some information and Wireshark screenshot on this blog. However, it...
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More Capture Details
In the previous post, I released my Ultimate PCAP which includes every single pcap I had so far on my blog. But that’s not all: I have some packets in there that were not yet published up to now. That...
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Types of VPN
Another small post out of my “At a Glance” series: The different types of virtual private networks (VPNs). Looking at Site-to-Site and Remote Access VPNs. This is one of many VPN articles on my blog....
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SharkFest’19 EUROPE: IPv6 Crash Course
I gave a session about IPv6 at SharkFest’19 EUROPE, the annual Wireshark developer and user community conference, named “IPv6 Crash Course: Understanding IPv6 as seen on the wire“. The talk is about...
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UK IPv6 Council Spring 2020: Incorrect Working IPv6 Clients & Networks
I did a short presentation at the spring 2020 roundtable of the UK IPv6 Council. The talk was about a case study I did with my NTP server listed in the NTP Pool project: For 66 days I captured all NTP...
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Slowing down my Blogging Rate
A few days ago, my blog turned seven (7). Wow! And this post right here is number 329. This is roughly one post per week over the last seven years. Not bad. ;D I can’t believe I was able to publish...
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Certificate Transparency & Alternative Name Disclosure
Maybe you’ve heard of Certificate Transparency and its log. Citing Wikipedia: “Certificate Transparency (CT) is an Internet security standard and open source framework for monitoring and auditing...
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Palo Alto GRE Tunnel
Since PAN-OS version 9.0 you can configure GRE tunnels on a Palo Alto Networks firewall. Greetings from the clouds. As always, this is done solely through the GUI while you can use some CLI commands to...
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A Little Printing Please – Packet Capture
Uh, I wasn’t aware of so many different printing protocols. Do you? While I was trying to solve a little printing problem I took a packet capture of three different printing variants over TCP/IP: Raw...
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iperf3 on a FortiGate
This is a really nice feature: you can run iperf3 directly on a FortiGate to speed-test your network connections. It’s basically an iperf3 client. Using some public iperf servers you can test your...
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More Capture Details II
An updated version of my Ultimate PCAP is available. It features some more network protocols that I will depict in this blog post. It’s getting more special since the most common protocols were already...
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Route-Based VPN Tunnel Palo Alto Cisco ASA
More than 6 years ago (!) I published a tutorial on how to set up an IPsec VPN tunnel between a Palo Alto Networks firewall and a Cisco ASA. As time flies by, ASA is now able to terminate route-based...
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Route-Based VPN Tunnel FortiGate Cisco ASA
More than 6 years ago (!) I published a tutorial on how to set up an IPsec VPN tunnel between a FortiGate firewall and a Cisco ASA. As time flies by, ASA is now able to terminate route-based VPN...
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Zweite Philips Hue Bridge: Was ein Schmodder
Seit mehreren Jahren nutze ich Lampen von Philips Hue. Natürlich nicht nur Lampen, sondern auch Relais, Steckdosen, allerlei Schalter, Taster, sowie Hue Labs, Routinen, die Integration mit IFTTT, usw....
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Capturing – because I can: IS-IS, GLBP, VRRP
I am constantly trying to add more protocols to the Ultimate PCAP. Hence I used some time in my (old) Cisco lab to configure and capture the following protocols: IS-IS, GLBP, and VRRP. And since Alexis...
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Nping aka Layer 4 Ping
I was missing a generic layer 4 ping in my toolbox. Initially searching for a mere TCP ping, I have found Nping which completely satisfies my needs and gives so much more. ;) What’s a layer 4 ping, and...
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Services listening on IPv6 and IPv4 (or maybe not?)
The other day I wanted to verify whether a service running on my Linux server was listening on IPv6 as well as IPv4. It turned out that it wasn’t that easy to answer – if at all. Which ports are in the...
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Firewall Basics: Sent vs. Received Values
I got an interesting question through the comments section on my blog: What does “Bytes sent/ Bytes received” mean in ACC screen of Palo Alto firewall? I mean, if 500MB of packets are sent from a...
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DDIUGv3: Certificate Transparency Disclosure
Quite spontaneous I gave a small talk on the 3rd german DDI (DHCP/DNS/IPAM) user group which took place on June, 17th, 2021. (I was asked to do a talk just two days before the meeting.) It’s based on...
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