[dns-operations] If I were the suspicious type.... (was:DNSAmplification Attacks)

[Rick Jones]

> "Getting rid" of open recursers and blocking port 53 should have a very
> similar effect. 

For people who used to do stuff via port 25, there are alternatives yes? 
The ports associated with authenticated mail access?

Is a similar alternative available to users of port 53?

Is it sufficient to simply block 53/udp rather than 53/* ?

rick jones