I'm using network, not NetworkManager. I've got a bridge set up with my (one and only) ethernet point connected to it. I'm running fedora 31.
Randomly, when I reboot the system to get a new kernel or something, dhcp will fail to assign an IP address to the bridge. I'll reboot again and it will be OK (I have also been able to do an ifdown/ifup to get an IP addr).
I once found a web page that said STP (spanning tree protocol) slowed things way down, and with my config I can't possibly have any loops, so I disable STP. That did indeed make network startup far more reliable, but it still sometimes fails.
Does anyone else have this problem? Is there some magic I can perform to make it reliable? I don't have this problem when configured with a static IP, but they were redoing a lot of network infrastructure and recommended everyone switch to dhcp.
It also seemed very reliable before I created the bridge (but I need the bridge to run virtual machines).
Working from home, I've now become paranoid about installing updates that need a reboot for fear I won't be able to get to the machine again because the network never comes back up.
Maybe I should install a script in rc.local that checks to see if an IP address was defined, and reboots again if not :-).