shell:$ nslookup -timeout=2 -retry=1 'myacn.secure.force.com'
Server:		75.98.161.224
Address:	75.98.161.224#53

Non-authoritative answer:
myacn.secure.force.com	canonical name = usa652.sfdc-lywfpd.force.com.
usa652.sfdc-lywfpd.force.com	canonical name = usa652.sfdc-lywfpd.salesforce.com.
Name:	usa652.sfdc-lywfpd.salesforce.com
Address: 155.226.130.8
Name:	usa652.sfdc-lywfpd.salesforce.com
Address: 155.226.130.6
Name:	usa652.sfdc-lywfpd.salesforce.com
Address: 155.226.130.7