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 209-6-250-18.s2576.c3-0.wrx-ubr1.sbo-wrx.ma.cable.rcncustomer.com is not the root of its zone.
Instead, try zone transfer on sbo-wrx.ma.cable.rcncustomer.com .
Instead, try zone transfer on sbo-wrx.ma.cable.rcncustomer.com .