Till Maas

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Configure Network Cards by PCI Address with Ansible Facts


In this post, you will learn advanced applications of Ansible facts to configure Linux networking. Instead of hard-coding device names, you will find out how to specify network devices by PCI addresses. This prepares your configuration to work on different Red Hat Enterprise Linux releases with different network naming schemes.

Red Hat Enterprise Linux System Roles

The RHEL System Roles provide a uniform configuration interface across multiple RHEL releases. However, the names of network devices in modern Linux distributions can often not be stable for various releases. In the past, the kernel named the devices after their order of appearance. The first device got the name eth0, the next eth1, and so on.

To make the device names more reliable, developers introduced other methods. This interferes with creating a release-independent network configuration based on interface names. An initial solution to this problem is to address network cards by MAC address. But this will require an up-to-date inventory with MAC addresses of all network cards. Also, it requires updating the inventory after replacing broken hardware. This results in extra work. To avoid this effort, it would be great to be able to specify network cards by their PCI address. Continue reading