root@815340a37f0e:/# time curl www.google.com
...
real    0m5.132s
user    0m0.006s
sys     0m0.003s

当我做nslookup它非常快.

root@815340a37f0e:/# time nslookup google.com
Server:         8.8.8.8
Address:        8.8.8.8#53

Non-authoritative answer:
Name:   google.com
Address: 173.194.78.101
...
real    0m0.024s
user    0m0.010s
sys     0m0.005s