Akamai vs Cloudflare vs Fastly : whether Egress Proxy (on Private Relay) are NXDOMAIN

In my country (Tokyo, Japan), it seems like that

"Akamai Technologies, Inc.", "Cloudflare, Inc.", and "Fastly, Inc.",

are providing almost all the egress proxy for using Private Relay (and these are estimated by whois information).

Also I was able to resolve the domain of Akamai's egress proxy with nslookup, such as:

a[ppp-qqq-rrr-sss].deploy.static.akamaitechnologies.com
/* [ppp-qqq-rrr-sss] means available ipv4 address of egress proxy */

but I couldn't resolve Cloudflare's and Fastly's, with NXDOMAIN error.

I want to know how and why has this difference occurred between Cloudflare, Fastly and Akamai, still it's one and the same service.

Because I found that some web services limit the use for accesses from Akami's Egress Proxy only, thus I'm guessing that this difference (security settings?) is causing the inconvenience.

In addition, I would like to know if Apple is comfortable with the situation of egress proxy not in the DNS records. And I hope that near the future either specification would be standardized or users would be able to choose them.


By the way, I might be often assigned the following IP addresses:

so now you can check it.