[hydra-dev] requirement: ipv6 ?

[Simon Perreault]

On 2010-06-11 12:20, Olle E. Johansson wrote:
>> * Hydra MUST be capable of running in an ipv6-only network.
>> * Hydra MUST be capable of running in an ip4-only network.
>> * Hydra MUST be capable of running in a mixed ipv4 and ipv6 network.
>> * in a mixed ipv4/v6 network, all symbolic addresses addresses MUST be resolved giving preference to ipv6.
>> * Hydra must obey TTL for any cached addresses.
>>
>> Am I missing any at this level?  is there agreement?
> And we do need asynch dns from start as well as DNSsec support.

Be careful what you build into Hydra.

- Preference for IPv6: yes and no. If preference means "try IPv6 first,
then IPv4", sure, no problem. However, this does not happen at the time
of name resolution. The name resolution subsystem should return all
results. Then when you actually try to make a connection, you have a
list of addresses, sorted if you wish, that you try until one works.
Bonus points if you try them simultaneously.

- DNS caching should be done separately, in a proper DNS cache, not
within Hydra. For example, one could run Unbound (a lightweight caching
nameserver) on the same host as Hydra. There should be no caching at all
in Hydra itself. Otherwise you're just reinventing the wheel and
inevitably introducing tons of bugs.

- DNSsec should be built into the OS, not re-done separately in each and
every application. Hydra should not have to deal with that at all.

- Async DNS: YES! ;)

Simon
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