[nullc]

So for example, I applied updates to a set of fedora systems recently.

The updates to network manager decided to change network interface names from looking like enP51p1s0f0 to enP51p1s0f0np0. The rename broke the (also networkmanager) channel bonding configuration, resulting in them being unreachable and requiring a physical visit to get them back online.

Networkmanager adds a lot of automagic, but outside of simple widely used configurations ("laptop with wifi") it causes unpredictable and unreliable behaviour.

I especially like the standard fedora server install where the nics present during the install all get DHCP enabled on them, but only those nics. So if you move a network card to another PCI slot after the install it will mysteriously not work. ... I see nothing wrong with not automatically bringing up interfaces on a server, but mysteriously bringing up some and not others makes for mystifying and difficult to diagnose issues that no one seems to know how to fix.