Blog

I recently had an issue within the network of a customer who was experiencing a big amount of broadcast, unknown unicast and multicast – short BUM – traffic within one of his layer 2 network segments. My customer is a company which is offering dedicated servers and virtual machines to all sorts of customers and with all sorts of hardware configurations. During the last years, they did not invest much time and money into ther network which is why there are no filters for spoofed/forged traffic and loops in place by now....

Due to a software issue on one of our QFX5100 switches, we’ve decided to reinstall the software on the device via the USB reinstallation method. We tried at multiple times to boot the switch from the USB thumb drive without success, even trying multiple different USB thumb drives and different methods to write the installation image onto the switch. The result kept the same: The device showed some cryptic text on the serial interface for a few seconds and then booted once again from the JunOS image residing on the SSDs....

Two years ago, I’ve used multiple Intel X710-DA4 NICs to built an EVPN Setup for my company level66.network. Whilst most of the connections to other peers worked quite well, I’ve had a few links which showed some strange issues. Most commonly the links were reported as flapping from the other peers or they just reported packetloss on their end. After quite some time of troubleshooting, switching optics and using different ports we found the solution....

Some time ago, I built my own Stratux Air Traffic Receiver which I used to show other airplanes on my electronic flight bag. Since a few flights, I am trying the app SafeSky. SafeSky uses multiple datasources from the internet to gather and display other traffic in EFB like ForeFlight and SkyDemon. The app runs on the same device as the navigation software, exporting the data into the local network via messages in the GDL90 format similar to the Stratux....

During the boot-process of my SG115 appliance with OPNsense I stubled over a issue with the configuration of the BIOS settings of the appliance. During the initialization of USB, the kernel died and moved over to the debug-mode leaving the installation of OPNsense unfinished. usbus0: EHCI version 1.0 usbus0 on ehci0 usbus0: 480Mbps High Speed USB v2.0 isab0: <PCI-ISA bridge> at device 31.0 on pci0 isa0: <ISA bus> on isab0 acpi_button0: <Power Button> on acpi0 acpi_button1: <Sleep Button> on acpi0 acpi_tz0: <Thermal Zone> on acpi0 atkbdc0: <Keyboard controller (i8042)> at port 0x60,0x64 on isa0 atkbd0: <AT Keyboard> irq 1 on atkbdc0 NMI ISA 20, EISA 0 NMI/cpu0 ....