2个提供在线查询服务的网站

http://ping.eu，

Choose function:

Ping – Shows how long it takes for packets to reach host Traceroute – Traces the route of packets to destination host from our server DNS lookup – Look up DNS record WHOIS – Lists contact info for an IP or domain Port check – Tests if port is opened on specified IP Reverse lookup – Gets hostname by IP address Proxy checker – Detects a proxy server Mail relaying – Tests relaying capabilities of specified mail-server Bandwidth meter – Detects your download speed from our server Network calculator – Calculates subnet range by network mask Network mask calculator – Calculates network mask by subnet range Country by IP – Detects country by IP or hostname Unit converter – Converts values from one unit to another

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www.network-tools.com(通过这个服务查询dns记录，所得结果很准确）