ip-81-201-153-23.static.reverse.dsi.net IXFR zone transfer

Changes since SOA version

IXFR is a zone transfer request that returns changes since a specific SOA version. Enter the SOA version to request changes since then.

Not an apex domain The domain ip-81-201-153-23.static.reverse.dsi.net is not the root of its zone.
Instead, try zone transfer on dsi.net .