1238106SdesIntroduction 2238106Sdes=================================== 3238106Sdes 4238106Sdes**Unbound** 5238106Sdes 6238106Sdes `Unbound`_ is an implementation of a DNS resolver, that performs caching and DNSSEC validation. 7238106Sdes Together with unbound, the libunbound library is provided. 8238106Sdes This library can be used to convert hostnames to ip addresses, and back, as well as obtain other information. 9238106Sdes Since the resolver allows to specify the class and type of a query (A record, NS, MX, ...), this library offers powerful resolving tool. 10238106Sdes The library also performs public-key validation of results with DNSSEC. 11238106Sdes 12238106Sdes .. _Unbound: http://www.unbound.net/documentation 13238106Sdes 14238106Sdes**pyUnbound** 15238106Sdes 16238106Sdes The pyUnbound is an extension module for Python which provides an object-oriented interface to libunbound. 17238106Sdes It is the first Python module which offers thread-safe caching resolver. 18238106Sdes 19238106Sdes The interface was designed with the emphasis on the simplicity of use. 20238106Sdes There are two main classes :class:`unbound.ub_ctx` (a validation and resolution context) and :class:`unbound.ub_result` which contains the validation and resolution results. 21238106Sdes The objects are thread-safe, and a context can be used in non-threaded as well as threaded environment. 22238106Sdes Resolution can be performed blocking and non-blocking (i.e. asynchronous). 23238106Sdes The asynchronous method returns from the call immediately, so that processing can go on, while the results become available later. 24238106Sdes 25238106Sdes**Features** 26238106Sdes * customizable caching validation resolver for synchronous and asynchronous lookups 27238106Sdes * easy to use object interface 28238106Sdes * easy to integrate extension module 29238106Sdes * designed for thread environment (i.e. thread-safe) 30238106Sdes * allows define and customize of local zone and its RR's during the operation (i.e. without restart) 31238106Sdes * includes encoding functions to simplify the results retrieval 32238106Sdes * Internationalized domain name (`IDN`_) support 33238106Sdes 34238106Sdes .. _IDN: http://en.wikipedia.org/wiki/Internationalized_domain_name 35238106Sdes 36238106Sdes**Application area** 37238106Sdes * DNS-based applications performing DNS lookups; the caching resolver can reduce overhead 38238106Sdes * Applications where the validation of DNS records is required 39238106Sdes * Great solution for customizable and dynamic DNS-based white/blacklists (spam rejection, connection rejection, ...) using the dynamic local zone manipulation 40