I'm not sure if it Covers IRR.
But considering IRR is an extension of Whois...

Arin keeps the service of "whowas"
https://www.arin.net/reference/research/whowas/
I suggest you take a look there.

And also, some IRRs keeps an archive folder on the FTP.
ftp://ftp.radb.net/radb/dbase/archive/

ftp://rr.level3.net/pub/rr/archive.mirror-data/

Em qua., 24 de fev. de 2021 às 05:03, Lars Prehn <lprehn@mpi-inf.mpg.de> escreveu:

Does anybody have (somewhat frequent, e.g., monthly) snapshots of the
various IRR databases lying around? Any snapshot since 2010 would be
helpful!

Best regards,

Lars