On October 30, 2013 at 19:07 Valdis.Kletnieks@vt.edu (Valdis.Kletnieks@vt.edu) wrote:
On Wed, 30 Oct 2013 21:33:38 -0000, Nolan Rollo said:
So in the four examples below, 3 of them preface the IP with an alpha character. Charter however, starts the rDNS off with a number. I'm not arguing with anyone but what potential problems could that cause with DNS?
Only if the system involved got on the net before 3com did (as RFC1123 specifically relaxed this requirement back in 1989).
And at that point, Indiana Jones would say "It belongs in a *museum*".
Back when I put Boston University on the net, pre-DNS, an accidentally included host name with a leading digit submitted for the HOSTS.TXT file brought down probably over half the net, many many unix systems. There was a bug in the program which converted from the HOSTS.TXT format to the unix /etc/hosts format. It went into a loop filling the root partitions which in those days hung a unix system hard, and many sites used unix systems as their main or only internet connection, no fancy on-site routers back then. Typically sites loaded the new HOSTS.TXT file after (or exactly at) midnight automatically so not a lot of systems staff around to recover which made it all the more painful. So I heard a lot about this "no leading digits in host names rule" the next day though when everyone calmed down it was agreed that the conversion program shouldn't have behaved so poorly. -- -Barry Shein The World | bzs@TheWorld.com | http://www.TheWorld.com Purveyors to the Trade | Voice: 800-THE-WRLD | Dial-Up: US, PR, Canada Software Tool & Die | Public Access Internet | SINCE 1989 *oo*