Ubuntu 20.04 not resolving local network hostnames

An Ubuntu 20.04 laptop installation started not being able to resolve the names of hosts in the same local network. Although the host names were registered with the router, the laptop wouldn't be able to resolve those host names. Surprisingly, neither netbios resolution worked (although nbtscan would find those hosts). The solution is to bypass … Continue reading Ubuntu 20.04 not resolving local network hostnames

Nautilus browsing large windows share is slow

When browsing large windows (samba) shares with Ubuntu Nautilus (that's the equivalent of the Windows File Explorer) I observed that shares which include many files and directories (a few hundred) take a few seconds to browse over WiFi, but almost instantly display over a fast LAN. A similar difference in speed is noticeable when searching … Continue reading Nautilus browsing large windows share is slow

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