Set network interface speed with systemd-networkd

Sometimes automation is your best friend and sometimes it isn’t. Typically, when two devices are connected via ethernet cables, they negotiate the best speed they can manage across a network link. They also try to agree on whether they can run full or half duplex across the network link. Most of the time, this works beautifully. It can break down with strange networking configs, damaged adapters, or finicky cables....

2021-08-20 · 3 min · Major Hayden

systemd-networkd on Ubuntu 16.04 LTS (Xenial)

My OpenStack cloud depends on Ubuntu, and the latest release of OpenStack-Ansible (what I use to deploy OpenStack) requires Ubuntu 16.04 at a minimum. I tried upgrading the servers in place from Ubuntu 14.04 to 16.04, but that didn’t work so well. Those servers wouldn’t boot and the only recourse was a re-install. Once I finished re-installing them (and wrestling with several installer bugs in Ubuntu 16.04), it was time to set up networking....

2017-01-15 · 3 min · Major Hayden

Tinkering with systemd’s predictable network names

I’ve talked about predictable network names (and seemingly unpredictable ones) on the blog before, but some readers asked me how they could alter the network naming to fit a particular situation. Oddly enough, my Supermicro 5028D-T4NT has a problem with predictable names and it’s a great example to use here. The problem There’s plenty of detail in my post about the Supermicro 5028D-T4NT, but the basic gist is that something within the firmware is causing the all of the network cards in the server to show up as onboard....

2016-01-20 · 3 min · Major Hayden

GRE tunnels with systemd-networkd

Switching to systemd-networkd for managing your networking interfaces makes things quite a bit simpler over standard networking scripts or NetworkManager. Aside from being easier to configure, it uses fewer resources on your system, which can be handy for smaller virtual machines or containers. Managing tunnels between interfaces is also easier with systemd-networkd. This post will show you how to set up a GRE tunnel between two hosts running systemd-networkd. Getting started You’ll need two hosts running a recent version of systemd-networkd....

2015-10-16 · 5 min · Major Hayden

Using systemd-networkd with bonding on Rackspace’s OnMetal servers

I’ve written about systemd-networkd in the past and how easy it can be to set up new network devices and tunnels. However, the documentation on systemd-networkd with bonding is a bit lacking (but I have a pull request pending for that). Rackspace’s OnMetal Servers are a good place to test since they have bonded networks configured by default. They’re also quite fast and always fun for experiments. To get started, head on over to the Rackspace Cloud control panel and build a compute-1 OnMetal server and choose Fedora 22 as your operating system....

2015-08-21 · 8 min · Major Hayden