Speaker
Kazunori Fujiwara
(Japan Registry Services Co., Ltd)
Description
CNAME resource records have been widely used since RFC 1034 and 1035. However, it is well known that using CNAMEs increases the work required for name resolution. The interpretation of the wire format, including CNAME responses, is clear but very complex. It is performed within the application process using libc'sgetaddrinfo() and gethostbyname(), so interpreting complex CNAMEs takes time. In this presentation, we will investigate the current state of CNAMEs using top domain name lists and show that up to nine levels of CNAMEs are in use and that several well-known services use multi-level CNAMEs. We will also investigate queries and responses at an actual university and show the number of CNAME levels used by users.
| Talk duration | 10 Minutes (+5 for Q&A) |
|---|
Primary author
Kazunori Fujiwara
(Japan Registry Services Co., Ltd)
Co-author
Dr
Akira Sato
(University of Tsukuba)
