Review bonding support in stboot
Review what bonding support we need in stboot. To summarize recent discussions:
- stboot itself does not need much of the benefits that bonding can provide (redundancy and improved throughput), it's typically the booted os package that benefits from these things.
- The reason stboot needs to be aware of bonding, is to enable network boot in environments where its closest switch is configured in a way that breaks connectivity unless bonding is negotiated successfully. This scenario is the most relevant for testing of stboot bonding.
- So far, the only bonding mode in actual use is 802.3ad. Since this way of bonding is intended to support autoconfiguration (thanks to lacp, the link aggregation control protocol), maybe dropping support for other bonding modes could make things simpler.
- stboot bonding currently requires the host config to enumerate all involved network interfaces. With 802.3ad bonding, it would probably be feasible with an automatic bonding mode, that sets all ethernet ports as lacp active, with the same lacp "key", and let autoconfiguration do its thing. One uncertainty is how to handle the case that the server is connected to multiple switches; ideally, one would want to automatically get multiple bondX-interfaces, one for each link aggregation group ("LAG") established by lacp, and use dhcp on each of them.