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 643ff68a3b8270006df8bec8d72faa60.cb77fd3cd80197671fc0946a1ded507b.comodoca.com is not the root of its zone.
Instead, try zone transfer on comodoca.com .
Instead, try zone transfer on comodoca.com .