Re: [exim] Tricky DNS servers [OT]

On 5/20/2012 8:25 AM, Jonas Eckerman wrote:
> On 2012-05-18 23:59, Marc Perkel wrote:
>
>> Here's a possible example. There are servers out there that return
>> country codes of IP addresses. But what about a country code for a host
>> name? You would have to do an IP lookup on the host and then use the IP
>> to get a country code.
>
> I don't see this as a problem, since it actually spreads the load of
> the loookup to different DNS servers and proxies and the client.
>
> Considering lookups done by an MTA or anti-spam system, the system is
> likely to lookup the IP address of any "interresting" hostname anyway
> so the result of that lookup should be in the cache allready except
> for the first lookup.
>
>> So - is there source code for something like this
>
> Obviously, yes. There are open source DNS servers that can do
> recursion when answering DNS queries. The source code for such a
> server has the building blocks you need for your idea.
>
> > or a DNS server with a scripting language?
>
> What about a DNS server written in a scripting language?
>
> <http://search.cpan.org/~olaf/Net-DNS-0.68/lib/Net/DNS/Nameserver.pm>
> <http://search.cpan.org/~bbb/Net-DNSServer-0.11/lib/Net/DNSServer.pm>
>
> There's likely to be at least one name server written in Python as well.
>
> Regards
> /Jonas

Thanks - this looks useful. Would python be faster?