bmanning@vacation.karoshi.com writes:
sorry for the poor attempt at humour... it was ancient practice to hang many names (not cnames) off a single IP address. all perfectly legal from a DNS POV.
rs.example.org. in a 10.10.10.53 nick.example.com. in a 10.10.10.53 bbss.isc.org. in a 10.10.10.53
it's also a poor practice operationally and one that's been deprecated for decades. i have a vague recollection of an rfc that said secondary nameservers ought not be connected to the same psn (remember those?) but my google fu fails me this early in the morning. nevertheless, i direct our august audience to rfc 1537 section 6 (october 1993). it's entirely reasonable to bring up this configuration misstep in the context of things acting hinky.
the punchline here was "anycasting" the address across multiple names. nary a routing trick in sight or in play.
"When *I* use a word," Humpty Dumpty said, in rather a scornful tone, "it means just what I choose it mean to neither more nor less."'
Lame I know.
as a tool to defeat the autobots who insist on "two nameservers" for a delegation - its kind of a clever poke in the eye w/ a sharp stick.
I hear the owners' manual for Fords tells you how to turn off the seat belt alarm too. Clever in rather the same way. -r