host-26-36.pool.t21v.ru 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 host-26-36.pool.t21v.ru is not the root of its zone.
Instead, try zone transfer on t21v.ru .