DNS-Resolver

Usage:

First run the resolver.py and the resolver will keep listening on the port.

$ python3 ./resolver.py port

Then you can start the client to send the query

$ python3 ./client.py 127.0.0.1 resolver_port name [type=A] [rd] [timeout=5]

Sample:

$ python3 ./resolver.py 5555
$ python3 ./client.py 127.0.0.1 5555 www.google.com

Overview

This is a basic version of DNS-Resolver. It implements a subset of the functionalities of dnspython. The resolver will listen for queries on a UDP port which is specified as a command-line argument. Clients will send queries from a UDP port which is automatically allocated by the operating system. Upon receiving a query, the resolver will repeatedly make non-recursive queries, starting at the root and following referrals, to iteratively resolve the query on behalf of the client.