Using DNS for 99,99% reliability

[Len Conrad]

>1) Does (most) nameservers on the net respect a TTL of only 5 minutes when
>caching our DNS records?
>     (or do they often keep the information over longer periods e.g 1 hour to
>avoid to much load)

most respect TTL's, some apparently have been haccked not to respect short 
TTL´s.

>2) How much traffic does a secondary DNS get when the primary is running?
>    (nothing at all or 5% or up to 50% ?)

impossible to say. All authoritative NS's are same availability.  For 
queyring, there is no concept of primary and secondary, as there is with MX 
servers.

BIND does RTT caculations to select the NS with lowest RTT.

Len

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