#!/usr/bin/env python3 import dns.edns import dns.message import dns.query import dns.resolver n = "." t = dns.rdatatype.SOA l = "199.7.83.42" # Address of l.root-servers.net i = "149.20.1.73" # Address of ns1.isc.org, for COOKIEs q_list = [] # A query without EDNS0 q_list.append((l, dns.message.make_query(n, t))) # The same query, but with EDNS0 turned on with no options q_list.append((l, dns.message.make_query(n, t, use_edns=0))) # Use use_edns() to specify EDNS0 options, such as buffer size this_q = dns.message.make_query(n, t) this_q.use_edns(0, payload=2000) q_list.append((l, this_q)) # With an NSID option # use_edns=0 is not needed if options are specified) q_list.append( ( l, dns.message.make_query( n, t, options=[dns.edns.GenericOption(dns.edns.OptionType.NSID, b"")] ), ) ) # With an NSID option, but with use_edns() to specify the options this_q = dns.message.make_query(n, t) this_q.use_edns(0, options=[dns.edns.GenericOption(dns.edns.OptionType.NSID, b"")]) q_list.append((l, this_q)) # With a COOKIE q_list.append( ( i, dns.message.make_query( n, t, options=[ dns.edns.GenericOption( dns.edns.OptionType.COOKIE, b"0xfe11ac99bebe3322" ) ], ), ) ) # With an ECS option using dns.edns.ECSOption to form the option q_list.append( (l, dns.message.make_query(n, t, options=[dns.edns.ECSOption("192.168.0.0", 20)])) ) for addr, q in q_list: r = dns.query.udp(q, addr) if not r.options: print("No EDNS options returned") else: for o in r.options: print(o.otype.value, o.data) print()