Domain Name System (DNS) Topic 2, Chapter 4 Network Programming Kansas State University at Salina
DNS Host name to IP address look up and reverse Hierarchical, distributed, cached database Many services provided by OS sock.connect( (hostname, port) ) socket.getaddrinfo( hostname, None )
Advanced DNS – DNSPython Lookup of MX records for sending is one example where you might need to program a DNS lookup. Need to add additional package for stand alone DNS lookups. Book discusses PyDNS, available from source forge. The package index on python.org suggests that DNSPython is a more popular DNS package.
DNSPython Also available from K-State Online Get the MX targets and preferences for a domain: import dns.resolver answers = dns.resolver.query(‘gmail.com', 'MX') for rdata in answers: print 'Host', rdata.exchange, 'has preference', rdata.preference