> So when IS-IS talks about topology discovery, it's talking about router > topology, with no knowledge of hosts or bridges or PHY technologies. I'm > sorry, but in a home network, the router topology is really the least of my > worries. Maybe to add some info from the HNCP front: HNCP also maintains a topology graph, so you will have a router topology independent of IS-IS in any case. Depending on how feature-rich your individual routers are (e.g. if at least one of your HNCP routers on a link runs an MDNS-proxy), you can enumerate all MDNS-capable devices on such links with the usual tools such as bonjour / avahi.
Beyond that you would need to run special (custom) services on each link, to e.g. let you query DHCP leases and/or NDP/ARP information from a router on each link but that is probably even less specified. However as for really transparent and unmanged switches or bridges you usually found in homes and that therefore do not announce themselves in any way you are probably out of luck in detecting them. > In short, I'm slowly coming to the following conclusions: > 1. Whatever diagnostics / topology discovery mechanisms may exists in IS-IS > are insufficient to be of any real use. So any argument for IS-IS based on > the existence of such diagnostics is irrelevant. [But I can be swayed from > this conclusion if someone can provide real info showing this conclusion is > wrong -- in an IS-IS load suitable for homenet routers.] > 2. Technologies that are not resilient against links that go up and down > frequently and for no apparent reason are useless in a home network. These > links are prevalent in the home network. And not just the wireless links. The > powerline and even coax links are also subject to this problem. In my > experience, these up-and-down links are The Number One Cause of home > networking issues today. I agree here, the problem is usually, you would need stuff like ethernet carrier detection to actively detect issues but that is more often than not masked by some (internal) switch or NIC somewhere in the path. Beyond that its a timer / packet loss thing, eventually any routing protocol will detect a longer lasting link failure and reorganize. Mesh routing protocols should usually have an advantage here since intermittent failure or lossy links is stuff they are explicitly designed for and so most of them can explicitly or implicitly (e.g. through dynamic metrics / link costs) provide feedback about quality of certain links. Then again this is all between individual routers. If you have a "funny" link with transparent cross-medium bridges e.g. router ---ethernet--- switch ---powerline--- bridged-AP --wifi-- router and all is essentially one L2-domain and then some clients somewhere in the mix, it will be problematic in any case. Cheers, Steven _______________________________________________ homenet mailing list homenet@ietf.org https://www.ietf.org/mailman/listinfo/homenet
