Author Archive for Jasper

  1. The Network Capture Playbook Part 6 – Planning Network Troubleshooting

    In the previous posts of the Capture Playbook series we discussed various approaches about how to record packets, but before going into more elaborate techniques of doing that we should talk about how a network troubleshooting project works, and especially how to plan a capture setup. In my experience this aspect of a troubleshooting is […]
  2. Sharkfest 2017 EU Recap

    In 2017 the Sharkfest Wireshark user and developer conference happened once again in Europe – in the Hotel Palacio Estoril in Portugal, to be more specific.
  3. Sharkfest 2017 US Recap – 10 years of Sharkfest!

    Time always flies at Sharkfest, the annual Wireshark conference, and the 2017 edition – being the 10th Sharkfest in the US – has been no exception. On Friday Sake and me talked about how fast the 3 day conference had felt and we both agreed that “hm, it seems just to have started moments ago […]
  4. A look at Paessler PRTG

    During Tech Field Day Extra at Cisco Live Europe 2017 one of the presentations we attended was from Paessler, about their PRTG monitoring tool. I had only seen it once before, during a penetration test I performed at a customer site – and since it was running with default credentials it gave a very nice […]
  5. Programmable ASICs in Cisco Switches

    I know what a Cisco switch is. I know what an ASIC is – a processor designed for a special purpose that it can do it’s job faster than a generic purpose processor running the job in software. What I didn’t know is that it was also possible to build programmable ASICs.
  6. Network Forensics Playbook – Banner Inspection and Client Origin

    I recently did a hands-on-no-slides presentation at a very small security conference end of last year where I demoed some of the typical things I do when performing a network forensics analysis, using tshark, Wireshark and TraceWrangler. I’ll use these blog posts as a transcript of what I did, so that it’s easy to read […]
  7. The Network Capture Playbook Part 5 – Network TAP Basics

    Most network captures are recorded using SPAN ports, as we’ve seen in the previous part of this series. Now that we know what SPAN is all about, it’s time to find out what TAPs are all about, and why you would want (or need) to use them in network capture. TAP is an acronym for […]
  8. The Network Capture Playbook Part 4 – SPAN Port In-Depth

    We have briefly covered SPAN ports in previous posts of this series, but there are so many things to consider that we have to look at the advantages and problems more closely. Even more so since it looks like there is a constant “battle” going on between SPAN and TAP supporters – some analysts will […]
  9. The Wireshark Q&A trace file sharing tutorial

    In many of those cases the person asking a question on the Wireshark Q&A site posts screenshots or ASCII dumps of the packet list, which is very hard to work with when you’re trying to help. It is much easier if you can get a PCAP or PCAPng file instead, but there are two major […]
  10. The Network Capture Playbook Part 3 – Network cards

    One of the most common answers that come to my mind when being asked questions during or after a talk at a conference is the famous phrase “it depends…”. This may sound unsatisfactory at first, but the problem with a lot of questions regarding network analysis (and packet capture) is that there are always so […]