Now that my fight with bgp is over, I have a #linux#networking question for you. A bridge interface is pretty much a sowtware representation of a switch, with one of its ports connected to the linux host. Now, that one port will be DOWN if no other interface is enslaved to that bridge, meaning you can't e.g. run a dhcp sever on that bridge (kea stubbornly refuses to operate on a downed interface; I don't blame it).
I had a few discussions with @oleksandr and he suggested to plug a veth into my bridge. Well, now it's always up (because there's always something plugged into it), but it feels like I use up two ports of the switch by the same machine. It's slightly confusing as to wether I should use the bridge interface or the veth interface. In practice it seems that removing all ip addresses and routes from the bridge and only using the veth would work, but it also seems excessive. Should I just enslave a dummy0 into the bridge so it goes up and use the bridge interface instead?
How do you people solve the problem of needing to have the bridge up before anything is enslaved to it (i.e. running dhcp, dns and such on the bridge interface while no VMs are up, yet)?
