RIPE our of IPv4

Sun Dec 1 02:01:36 UTC 2019

On 11/30/19 8:55 PM, Valdis Klētnieks wrote:
>> User apps prefer IPv6, Netflix stops, users complain
> And fallback to IPv4 fails to happen, why, exactly?

Inability to signal application-level failure on IPv6 and that fallback to IPv4 would succeed.

Netflix definitely exhibits this.  I've also noticed that a lot of Cloudflare-hosted apps/sites block AS6939 outright which mostly only affects IPv6 as they don't actually originate much end-user-facing IPv4 space.  The result is an HTTP/403 which most browsers do not interpret as a response that could be remedied by "happy eyeballs" type behavior.  Whether banning an entire ASN like that in precisely a situation where this kind of thing is likely to occur is a good practice or not is left as an exercise to the reader.
-- 
Brandon Martin