before: ixfr falls back to axfr only if valid, but negative reply, e.g. NOTAUTH, journal inconsistency.. after: ixfr falls back to axfr in any case ixfr fails, e.g. malformed reply packet
before: ixfr falls back to axfr only if valid, but negative reply, e.g. NOTAUTH, journal inconsistency.. after: ixfr falls back to axfr in any case ixfr fails, e.g. malformed reply packet