Archive for the ‘Wireshark’ category

  1. Spurious Retransmissions

    Update: since Wireshark version 1.12 is out, lots of people look for the meaning of “spurious retransmissions”, so I changed the post a little to make it easier to find what you’re looking for. Today, while doing a lot of testing of my trace handling code as well as in preparation for the upcoming Sharkfest […]

  2. Name Resolution Denial of Service

    Today I was using a combination of dumpcap and Wireshark to run a network forensics investigation against a server that may have been compromised. A couple of malicious files had been reported by the virus scanner, so I had to take a closer look at what it was doing in the network. Actually, dumpcap was […]

  3. The notorious Wireshark “Out of Memory” problem

    It is one of the most common question on the Wireshark Q&A site: “I have xyz gigabyte of memory, but still Wireshark crashes when I try to capture data”, with xyz being a more or less impressive (or even ridiculous) amount of memory. This is how a typical crash looks like (your mileage may vary):

  4. Wireshark GeoIP resolution setup

    One of the many features Wireshark provides is the name resolution for various protocol layers, and I have to admit that – at least for me – some of them are really helpful while others (well, one of them, to be more specific) annoy the hell out of me. I really like MAC layer resolution, […]

  5. Capturing damaged frames

    One of the questions that I often got in my network analysis classes was how to capture damaged frames. It is an obvious thing to ask, since frames with bad checksums will most certainly have to be retransmitted or are at least a nice indicator that something went wrong while transporting the frame.

  6. The packet analysts “self check”

    One thing all members of our packet analysis team do every once in a while is to check what their own laptop/PC is doing on the network – meaning, that we just close all programs and run Wireshark to see what packets are still going in and out. If we’re in paranoid mode for some […]

  7. Learning something new every day…

    Today, a question was posted on ask.wireshark.org, about Wireshark becoming more than just a packet analyzer since it could already read MP3, JPG and other file formats.