Smaller than a /24 for BGP?

Sun Jan 29 01:11:48 UTC 2023

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