internet_address_survey_reprobing_it25w-20090319 (03/19/2009 to 04/02/2009)

To collect this data, a subset of Internet IP addresses was pinged by sending ICMP ECHO_REQUEST (PING) packet. The response (if it ever came within 11 minutes time interval) was recorded in this data set. Probe was repeated every 11 minutes. In all, 22370 netblocks (/24 subnets) were periodically reprobed.为构建本数据集，研究人员通过发送互联网控制消息协议（ICMP）回显请求（ECHO_REQUEST，即PING）数据包，对部分互联网IP地址执行PING探测。若探测响应在11分钟的时间区间内返回，则将其收录至本数据集。所有探测任务每11分钟重复执行一次。本次数据集总计覆盖22370个网络块（/24子网），并对这些网络块开展周期性重探测。