shell:$ nslookup -timeout=2 -retry=1 'cert.int-x3.letsencrypt.org'
Server:		75.98.161.224
Address:	75.98.161.224#53

Non-authoritative answer:
cert.int-x3.letsencrypt.org	canonical name = crl.root-x1.letsencrypt.org.edgekey.net.
crl.root-x1.letsencrypt.org.edgekey.net	canonical name = e8652.dscx.akamaiedge.net.
Name:	e8652.dscx.akamaiedge.net
Address: 23.222.21.129
Name:	e8652.dscx.akamaiedge.net
Address: 2600:1405:d400:284::21cc
Name:	e8652.dscx.akamaiedge.net
Address: 2600:1405:d400:286::21cc