I am testing out sites' TLS configuration with the SSL Testing service at www. ssllabs. com/ ssltest. I have typed in the hostnames deadpool.turnitin.com and sac2.turnitin.com. Somehow, SSLlabs is finding 4 IP addresses for each host, they seem to the correct since I get the cert I want for each of them. For example:
deadpool. turnitin. com
CNAME for legacy. turnitin. map. fastly. net, 126.96.36.199:
Anycast IPs 188.8.131.52, 184.108.40.206, 220.127.116.11, 18.104.22.168
sac2. turnitin. com
CNAME for turnitin. map. fastly. net, 22.214.171.124:
126.96.36.199, 188.8.131.52, 184.108.40.206, 220.127.116.11
The the apex A record for turnitin.com is 18.104.22.168.
How do you suppose SSLlabs is deducing the anycast IP addresses for these, given the single IP linked to the CNAME? It can’t be from DNS (at least IPV4 DNS) Do you get these from anycast/BGP? IPV6 DNS?
(Sorry about the weirdly formatted host names. The forum SW thinks they are links and won’t let me post them.)