shell:$ nslookup -timeout=2 -retry=1 'mmsc.mobile.att.net'
Server:		1.1.1.1
Address:	1.1.1.1#53

Non-authoritative answer:
mmsc.mobile.att.net	canonical name = mmsc.gslb.mobile.att.net.
Name:	mmsc.gslb.mobile.att.net
Address: 166.137.121.1