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Resolving product shortcomings.

Tuesday, November 10, 2020

power-guard-safe.jpg Recently I bought a document safe. This was necessary because some types of documents need to be kept safe even during still ongoing COVID-19 home office. I choose a model with a security grade necessary to legally comply required by the type of documents I work with. And I choose one with a digital keypad so I don’t have to have a physical key but a numeric code. From the time it was ordered, it took about a week to be delivered and some effort (weighs around 50kg) to get it into place. After I put in a fresh 9V battery, set up a security code, and put in some documents, I was done - I thought ….

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HDD Rescue Adventures

Friday, September 11, 2020

hdd-rescue-s.jpg As everybody knows “Make Backups (more than one!!) of your data!!” nowadays is as important as gaining enough sleep or eating healthy. But sometimes you are completely unprepared. This is exactly what happened to me a few days ago. A hard disk with very important source code for a project I’m currently working on suddenly stops working and the last backup was … some weeks ago.

So what to do? Besides calling me self a jackass I had to find a way to get back the data. After researching prices of some professional data rescue companies I came to the conclusion that trying to recover the data myself (and rewriting the lost source code in case my rescue attempt fails) would be cheaper and faster (project deadline is approaching with rapid steps).

 
 
 
 
 
 

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Extending Net-SNMP with Python3

Thursday, September 10, 2020

PyAgentX3 is a pure Python3 implementation of the AgentX protocol (RFC 2741).
It will allow to extend an SNMP agent (e.g Net-SNMP snmpd) by writing AgentX subagents without modifying the original SNMP agent.

RFC 2741: Agent Extensibility (AgentX) Protocol

Code and samples can be found on github.

It features:

  • Open a session with AgentX master, e.g. net-snmpd snmpd, and register a new session.
  • Send Ping request.
  • Register multiple MIB regions.
  • Multiple MIB update classes with custom frequency for each.
  • Support snmpset operations.
  • Reconnect/Retry to master, in case the master restarted.
  • Support for SNMPv2 traps.

Arty-S7-50 MultiNet

Tuesday, June 2, 2020

arty_s7_50_multi_net_pcbs.jpg The prototype of my simple FPGA based SoC with multiple Ethernet interfaces worked so well that I decided to create a PCB for it and increase the number of network interfaces from two to four. It also includes a special PMOD connector for a SD-Card to boot a firmware or Linux from. Also two of the Arty’s four existing PMODs are also still available for extensions. PMOD-C and PMOD-D are no longer available as their pins are used for some of the Ethernet PHY modules.

Due to I/O limitations the Seven Segment Display was removed from the original design.
 
 
 
 
 
 
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fpga_net_1_l.jpg In my day to day business I work with Software Defined Networking (SDN) a lot. Especially with Open-Flow, Open-vSwitch and some commercial products.

Most of the time the projects are not “normal” ones where these techniques are used in larger scenarios like enterprise or data-center networks. Instead I use them on the other side of the scale in embedded environments for example to develop Space based satellite routers.

At the time of this writing we now have almost eight weeks lock-down due to the SARS-CoV-2 pandemic. This means no travel time to my office and instead working from home. So this spare time must be filled with some experiments. Unfortunately at home I don’t have the resources I normally have at my workplace. So no fancy, multi k-euro development boards and tools. Wanting an embedded system with at least two Ethernet interfaces I looked around in my electronic junkyard and found some interesting components which might give a not so bad platform for some networking experiments. Especially low level Ethernet packet handling (filtering, modifying) is on of my interests. Maybe playing with P4, NetCope, or P4FPGA without spending a fortune.

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