shell:$ nslookup -timeout=2 -retry=1 'dktt.mobifone.com.vn'
;; communications error to 1.1.1.1#53: timed out
Server:		8.8.8.8
Address:	8.8.8.8#53

Non-authoritative answer:
Name:	dktt.mobifone.com.vn
Address: 45.121.26.119