Category: network

Resetting a PCI device

The Wi-Fi adapter on my VivoBook 17 has been acting up under Ubuntu 18.04 LTS insofar that at a random point in time, possibly accelerated by power saving features, the Wi-Fi will stop working with suspicious syslog entries: ath10k_pci 0000:03:00.0: failed to wake target for read32 at 0x0003a028: -110 The usual tricks (suspend/resume, reload driver, … Continue reading Resetting a PCI device →

Software architecture for 5G networks

The 5G mobile network specification introduces network function virtualization [NFV] which enables mobile network operators (carriers henceforth) to expose network resources to business applications as PaaS solution building blocks [SBB]. Naturally, this moves 5G into the focus of software architecture. Unsurprisingly, the NFV specs detail services from the carrier's  point of view, so they are … Continue reading Software architecture for 5G networks →

Securing a development server

In this post I talk about setting up and securely operating development tools like Jenkins and Gitlab on a server connected to the internet. All applications run behind a firewall and a reverse HTTP proxy which allows only HTTP requests from selected users through who authenticate themselves with client certificates. Putting web-facing software on the … Continue reading Securing a development server →

Using Blogger with a custom domain: the zonefile dot problem

A quick note to myself the next time I stumble over this: when you instruct Blogger to map the blog to a 3rd party (custom) domain it basically instructs you to add three entries to your domain's zone file: 1. a mapping from the domain to ghs.google.com 2. a mapping from some weird subdomain you'll … Continue reading Using Blogger with a custom domain: the zonefile dot problem →

Running a website on ip6

I started quite a while ago moving a pet project to ip6. While it doesn't involve any programming per se, it turned out to be quite a complicated process involving multiple configuration steps. Thus, for your enjoyment I present: running a website on ip6 with Ubuntu 14.04 (older versions won't work because their kernel doesn't … Continue reading Running a website on ip6 →

Linux picking the best access point in a WLAN with repeaters

In many larger WLAN setups you'll find repeaters or extenders which spread the WLAN to farther places on the floor. Often they are set up in such a way that they use the same WLAN name (SSID) and password. In that case the WLAN hardware on your laptop will pick the best access point and … Continue reading Linux picking the best access point in a WLAN with repeaters →

Automatically starting an SSH tunnel in Ubuntu

As I am a frequent guest in public WLANs I spent some time looking into ways to connect safely to both the corporate network and the rest of the internet while enjoying the amenities of a cafés' or hotel's wifi. Because of its simplicity and universal availability I like SSH tunnels which are easily set … Continue reading Automatically starting an SSH tunnel in Ubuntu →