named: error sending response: not enough free resources

[Tim Judd]

<snip>

- the network/LAN named tries to sent UDP packet is somehow flooded.
>>
>
>   Dns is probably fairly busy. It's the primary authorative dns for
>   some busy domains. Is there a setting I can do to increase the
>   limits of UDP packets to keep it from causing problems?
>
</snip>

If you extend the SOA record to extend the refresh/TTL etc, you can lighten
the load, until that refresh hits again.  There is no solution other than to
bump up the bandwidth, it seems.