Internet surveys

19990131: PTR records
19991221: PTR records

19961127: SMTP software
19970813: SMTP software
19980511: SMTP software
20000402: SMTP software
20001001: SMTP software
20011003: SMTP software
Bogus popularity claims for Sendmail

19970426: SMTP extensions
19980508: SMTP extensions
19980511: SMTP extensions

What software packages are used to supply Internet services? What optional features do they support? How quickly do old bugs die out, and how quickly are new standards adopted? I'm conducting a series of scientific surveys to answer these questions.

All surveys are conducted from network-surveys.cr.yp.to (131.193.178.100).

Current surveys

I often survey PTR records.

I often survey SMTP software.

I often survey DNS software.

Completed surveys

How many hosts are visible on the Internet? 19981201-19990131: There are PTR records for more than 51 million IP addresses. 19991221: There are PTR records for more than 83 million IP addresses. 20010928: There are PTR records for approximately 168 million IP addresses.

What software is used for SMTP servers? 19961127: 80% of the reachable servers were running sendmail under UNIX. (Followup surveys on 19970112, 19970218, 19970328; not reported here.) 19970813: 76% of the reachable servers were running sendmail under UNIX. 19980511: 63% of the reachable *.net mail exchangers were running sendmail under UNIX. 20000402: 55% of the reachable *.com mail exchangers were running sendmail under UNIX. 20001001: 47% of the reachable servers were running sendmail under UNIX. 20011003: 42% of the reachable servers were running sendmail under UNIX. Meanwhile, qmail jumped from 9% to 17%.

What software is used for FTP servers? 19970120: 75% of the reachable servers used ftpd or wuftpd under UNIX.

What are the EHLO responses from SMTP servers? 19970426: 69% of the reachable servers supported ESMTP. 19980508: 72% of the reachable servers supported ESMTP. 19980511: 90% of the reachable *.net mail exchangers supported ESMTP.

How many domains rely on dotted-decimal MX records? 20000225: There were roughly 15000 *.com domains whose MX records included reachable dotted-decimal IP addresses. Roughly 10000 of these domains had no other MX records.