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-130-250-129-0.buf.h5datacenters.com is not the root of its zone.
Instead, try zone transfer on buf.h5datacenters.com .
Instead, try zone transfer on buf.h5datacenters.com .