William Herrin wrote:
That multihomed sites are relying on the entire Internet for computation of the best ways to reach them is not healthy way of multihoming.
This was studied in the IRTF RRG about a decade ago. There aren't any other workable ways of multihoming compatible with the TCP protocol, not even in theory.
A decade? The problem and the solution was thoroughly studied by me long ago and the first ID was available already in 2000. The 5th version is here: https://datatracker.ietf.org/doc/html/draft-ohta-e2e-multihoming-05.txt I've found that you can access the first one by "Compare versions" feature of the web page.
So, another way of multihoming critically depends on replacing the layer-4 protocols with something that doesn't intermingle the IP address with the connection identifier.
Wrong. As is stated in my ID that: On the other hand, with end to end multihoming, multihoming is supported by transport (TCP) or application layer (UDP etc.) of end systems and does not introduce any problem in the network and works as long as there is some connectivity between the end systems. end to end multihoming may be supported at the application layer by trying all the available addresses, which is what DNS and SMTP are actually doing. TCP modification is just an option useful for long lasting TCP connections. Masataka Ohta