looking for hostname router identifier validation

Paul Ebersman list-nanog2 at dragon.net
Mon Apr 29 21:22:16 UTC 2019


ekuhnke> I would caution against putting much faith in the validity of
ekuhnke> geolocation or site ID by reverse DNS PTR records. There are a
ekuhnke> vast number of unmaintained, ancient, stale, erroneous or
ekuhnke> wildly wrong PTR records out there. I can name at least a half
ekuhnke> dozen ISPs that have absorbed other ASes, some of those which
ekuhnke> also acquired other ASes earlier in their history, forming a
ekuhnke> turducken of obsolete PTR records that has things with ISP
ekuhnke> domain names last in use in the year 2002.

That's because the version of perl required to run the perl script that
creates the ascii text PTR zone file is 4.x. perhaps? :)

bryan> I still see references to UUNet in some reverse PTRs.

bryan> So, uh, yeah.

The uu.net PTRs should mostly have been service machines, like
ns.uu.net, auth00.ns.uu.net (which horrifyingly do still
resolve). Routers should have been in alter.net, which I do still see in
traceroutes.



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