firewall.sielkamp.etc.tu-bs.de 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 firewall.sielkamp.etc.tu-bs.de is not the root of its zone.
Instead, try zone transfer on sielkamp.etc.tu-bs.de .