This web page documents the format of our Internet address IPv4 response history data. Our IPv4 response history data is available upon request.
An IPv4 response history data is a list of three-tuple, {IP addresses, its response history bitmap, estimation of its current responsiveness}. The "response" we mean here refers to response to ICMP echo request.
Our IPv4 response history is primiarily dervied from our Address Censuses, and we join all censuses data we have to produce the response history for every IP address appeared in censuses that at least for once was responsive. The response history of each IP address has the format of a bitmap. The "response" (or "responsive") we mean here refers to an ICMP echo reply being received, and we use a "1" in bitmap to represent this. Otherwise, a "0" is added in bitmap. Each bit in the bitmap represents the responsive record from one census.
We also provide a estimation score together with the response history for each IP address. The score, ranging from 0 to 99, could be used to predict the current responsive state of the IP address. The higher the score, more possible that the IP address would be responsive. We use the method described in our Hitlist paper to calculate the score and we use the records from the recent 16 censuses (last 16 bits of response history) as the input to the algorithm.
The format is a simple text file, one entry per line, with fields separated by tabs. The first line is a header indicating the columns' names:
#fsdb -F t hex_ip history score
The meaning of each column:
Here's a partial example of a file (with fake IP addresses):
#fsdb -F t hex_ip history score 0a0025d6 1ffffffff 99 0a002615 3ffff 99 0a002713 10000009 36 0a002a01 200020000 0