curl查看响应时间

curl -o /dev/null -s -w %{http_code}:%{http_connect}:%{content_type}:%{time_namelookup}:%{time_redirect}:%{time_pretransfer}:%{time_connect}:%{time_starttransfer}:%{time_total}:%{speed_download} http://www.baidu.com

http://blog.csdn.net/zhongyuan_1990/article/details/46634399

nslookup

yum -y install bind-utils
使用nslookup/host/dig命令

或者,tracert/traceroute/tracepath

php中的curl

curl_setopt($curl, CURLOPT_IPRESOLVE, CURL_IPRESOLVE_V4); //禁止解析IPV6 直接IPV4

http://stackoverflow.com/questions/8712167/curl-namelookup-time-of-10-seconds

或者,去修改系统的dns设置,或者去看看curl的