Tumbleweed - unplug one ethernet port and they all go down

I’m running Tumbleweed on an IBM POWER6 box and have a strange problem with the ethernet ports. There are four ports, 192.168.1.1 thru 192.168.1.4. When I unplug one ethernet cable the other remaining ports stop responding to pings. Plugging that cable back in brings all four ports back. What service or daemon is causing this? I disabled systemd-networkd-wait-online and systemd-networkd.service to no effect.

Hello and welcome here.

When one looks for help with bug searching, it is always very important to make a difference between ones conclusions and the hard computer facts. In this case, your title says that the NICs are down, but your technical description is that they do not respond to pings. That is not the same.

So when you think they are down, then please show us (and yourself) that that is the case by posting e.g. (as root)

ip addr

and of course before and after the unplugging. Only so we (and you) can see what is the difference.

Power6 is only a type of CPU, that won’t say anything about the hardware architecture of your box… You’ll likely need at least the model, maybe more. Or, physically open up your box and take a look.

Having seen a few weird multi-NIC cards used in IBM branded boxes, you may need to find out exactly what card is installed and its features.
So, for instance you might have your NICs configured to be ganged and if it’s being done in hardware you wouldn’t have noticed anything special in software…

TSU