On 1/22/21 9:02 PM, Maciej Żenczykowski wrote: > Why can't we get rid of the special case for 0 and simply make 1024 the > default value? That would work too. > > As for making it an RA option: it's not clear how that would work, the > use case I see for this is for example two connections to the internet, > of which one is clearly better (higher throughput, lower latency, lower > packet loss, etc) then the other. > > The upstream routers would have to somehow coordinate with each other > the metric values... that seems impossible to achieve in practice - > unless they do something like report expected down/up > bandwidth, latency, etc... While some sort of policy on the machine > itself seems much more feasible (for example wired interface > wireless > interface > cell interface or something like that) I was thinking the admin of the network controls the RAs and knows which paths are preferred over the admin of the node receiving the RA (not practical for a mobile setup with cell vs wifi, but is for a DC which is the driving use case). But it takes an extension to IPv6/ndisc to add metric as an RA option, so not realistic in a reasonable time frame.
