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 PHNX3-UBR6-4-hfc-0251-d17d3053.rdc1.az.coxatwork.com is not the root of its zone.
Instead, try zone transfer on coxatwork.com .
Instead, try zone transfer on coxatwork.com .