something about rrl
cathya at isc.org
Wed Sep 24 07:59:23 UTC 2014
On 22/09/2014 11:55, 陈超 wrote:
> Dear developers,
> I've recently encountered a problem with the response rate limit of bind-9.9.5.
> That is,after I configured RRL and started named,I noticed for those queries,BIND9 would do recursion first,and check the rate limit to decide whether it should send a response or not,later.
> Could you please tell me why RRL was applied in such a manner?If I really need to modify the BIND9 implementation to drop all those abused queries before recursions take place,can I just go ahead,without causing potential troubles?Is it risky?
> Any kind of advice will be appreciated.Thank you.
> Chao Chen
This is *response* rate limiting - a recursive server doesn't know what
response it should send to the client (if this is a new query for which
the answer is not in cache) until it has done recursion.
RRL was originally written to solve problems encountered by
authoritative server operators. I think you may have a different
problem that needs a different solution - possibly DNS RPZ.
By default Response Policy behaviour is also to recurse first, although
later versions of RPZ have the option 'qname-wait-recurse' that you can
use to change this if your policy depends on the query name rather than
information that can only be determined from the query response from the
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