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 94.132.232.128.in-addr.arpa.cam.ac.uk is not the root of its zone.
Instead, try zone transfer on in-addr.arpa.cam.ac.uk .
Instead, try zone transfer on in-addr.arpa.cam.ac.uk .