[nsd-users] Why doesn't UDP cause UDP?

[Paul Hoffman]

At 8:58 AM +0100 12/4/09, Matthijs Mekking wrote:
>Previously, NSD always made his IXFR requests over UDP.
>Since 3.2.0, we default to IXFR/TCP.
>The UDP option is too still make IXFR/UDP requests.
>We strongly recommend to use TSIG if you use IXFR/UDP.
>
>NSD will still try to AXFR the zone with TCP, if the zone's current
>serial is 0, or if the master server does not implement IXFR.

This new rule makes it impossible to start being a slave to a master that requires UDP, unless it will do AXFR. That is, even specifying "UDP" will not let NSD start be a slave because at first, the serial number will be 0. This seems like a pretty severe restriction in the name of forced safety.