shell:$ nslookup -timeout=2 -retry=1 'webto.salesforce.com'
Server:		75.98.161.224
Address:	75.98.161.224#53

Non-authoritative answer:
webto.salesforce.com	canonical name = login.salesforce.com.
login.salesforce.com	canonical name = login.l2.salesforce.com.
Name:	login.l2.salesforce.com
Address: 136.146.18.213
Name:	login.l2.salesforce.com
Address: 136.146.19.213
Name:	login.l2.salesforce.com
Address: 136.146.20.213
Name:	login.l2.salesforce.com
Address: 136.146.17.213