Pushing VLAN tags through unmanaged switches

Kenneth Finnegan writes: This year, I was designated as the computer network zonie, so it’s my job to make sure that there’s IP connectivity between all the major sites in the network. This involves building a computer network that includes a couple Internet hand-off points, multiple routers, several medium-range (2-5km) microwave links, QoS enforcement for […]

Tutorial: Nut/OS on Altera FPGA

Michael Fischer of emb4fun has a new tutorial on using Nut/OS on Altera FPGAs. His design uses the Altera DE0-Nano board and a self-made adapter equipped with a DM9000E-H board, and includes a short example for an Internet Radio. Michael’s tutorial is divided into three parts linked below: Part 1, Part 2, and Part 3. […]

Lower Webduino server overhead with a favicon.ico

Martin Lormes recently acquired an Arduino and Ethernet shield. Once he got the setup running on the web using the Webduino Arduino web server library, he checked the traffic using Wireshark and noticed that if the embedded server didn’t offer up a favicon.ico file when initially requested the browser would keep requesting the file. This […]


While most of us are familiar with packet capturing/sniffing programs such as Wireshark, it’s not always the most convenient or appropriate tool to use in every network monitoring situation. Henry Van Styn has written an excellent how-to tutorial on the uses of the Linux command line utility TCPDUMP, and why it may be all you […]

Free O’Reilly webcast: Core Network Protocols

O’Reilly is offering a free webcast on “Core Network Protocols: Two techniques you need to know.” The 60 minute presentation by Bruce Hartpence will be live this Friday, October 14, 2011, at 1 PM PT. In this webcast we’ll talk about address space, the purpose of the network mask and the reasons we manipulate network […]

How to build still another passive ethernet tap

firestorm_v1 from yourwarrantyisvoid has published this detailed tutorial on building and using a passive ethernet tap. His goal in this project is to facilitate network monitoring for intrusion detection purposes, and wanted hardware which will allow the monitoring for traffic without degrading performance.

Web platform: uIP TCP/IP stack with multitasking

There’s some new features in  Bonybrown’s  uIP TCP/IP stack project for the web platform. Some notable changes are: The code runs 3 “tasks” that it multitasks between. One for the IP stack, one for the serial port (debugging help) and another for a handler for telnet (port 23). The telnet server task is pretty easily […]

Web platform: uIP TCP/IP stack with interrupts, DMA

Here’s another update on the uIP TCP/IP stack port for the web platform. Bonybrown got the uIP stack to work with interrupts from the ENC28J60, and used DMA to transfer buffers to PIC memory. Performance wise – no real difference I can see from the ping times; theoretically, the biggest improvement will be in “responsiveness” […]