shell:$ nslookup -timeout=2 -retry=1 'fast.a.klaviyo.com'
Server:		75.98.161.224
Address:	75.98.161.224#53

Non-authoritative answer:
fast.a.klaviyo.com	canonical name = klaviyo-onsite.map.fastly.net.
Name:	klaviyo-onsite.map.fastly.net
Address: 146.75.10.133