For some reason, I came across a blog post by Gian Paolo called Small servers. This reminded me of some fairly old network protocols (that no one uses as far as I know) that are not in my Ultimate PCAP yet. Hence I took some minutes, captured them, and took some Wireshark screenshots. They are: echo, discard, daytime, chargen, and time. Mostly via TCP and UDP, and, as you would have expected, IPv6 and legacy IP.
I’m aware that this is not of interest to most of you. :) But for the sake of completeness, and because I love adding new protocols to the Ultimate PCAP, I added them though.
Continue reading Small Servers PCAP
I am currently working on a network & security training, module “OSI Layer 4 – Transport”. Therefore I made a very basic demo of a TCP and UDP connection in order to see the common “SYN, SYN-ACK, ACK” for TCP while none of them for UDP, “Follow TCP/UDP Stream” in Wireshark, and so on. I wanted to show that it’s not that complicated at all. Every common application/service simply uses these data streams to transfer data aka bytes between a client and a server.
That is: Here are the Linux commands for basic lab, a downloadable pcap, and, as always, some Wireshark screenshots:
Continue reading Basic TCP and UDP Demos w/ netcat and telnet