ssh vyos@vyos -- /opt/vyatta/bin/vyatta-op-cmd-wrapper show interfaces

set service dns forwarding cache-size 10000
set service dns forwarding system

# python3 <<'EOF'
> import socket
> import time
> import struct
> import random
> import sys
> 
> # --- Configuration ---
> DNS_SERVER = "8.8.8.8"
> DNS_PORT = 53
> QUERY_DOMAIN = "google.com"
> TIMEOUT = 1.0  # 1 second timeout
> 
> # --- Counters ---
> success_count = 0
> timeout_count = 0
> total_count = 0
> 
> def build_dns_query(domain_name):
>     # Standard DNS query header
>     transaction_id = random.randint(0, 65535)
>     flags = 0x0100  # Standard query
>     questions = 1
>     header = struct.pack('!HHHHHH', transaction_id, flags, questions, 0, 0, 0)
> 
>     # Question section
>     qname = b''
>     for part in domain_name.split('.'):
>         qname += struct.pack('B', len(part)) + part.encode('utf-8')
>     qname += b'\x00'  # End of QNAME
> 
>     qtype = 1  # A record
>     qclass = 1 # IN class
>     question = struct.pack('!HH', qtype, qclass)
> 
>     return header + qname + question
> 
> def print_stats():
>     global success_count, timeout_count, total_count
>     if total_count == 0:
>         return
>     
>     timeout_rate = (timeout_count / total_count) * 100
>     status_line = (
>         f"\rSuccess: {success_count} | "
>         f"Timeouts: {timeout_count} | "
>         f"Total: {total_count} | "
>         f"Timeout Rate: {timeout_rate:.2f}%  "
>     )
>     sys.stdout.write(status_line)
>     sys.stdout.flush()
> 
> print(f"--- Starting DNS timeout test against {DNS_SERVER} (Ctrl+C to stop) ---")
> 
> try:
>     while True:
>         total_count += 1
>         query = build_dns_query(QUERY_DOMAIN)
>         
>         sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
>         sock.settimeout(TIMEOUT)
>         
>         try:
>             sock.sendto(query, (DNS_SERVER, DNS_PORT))
>             data, addr = sock.recvfrom(512)
>             success_count += 1
>         except socket.timeout:
>             timeout_count += 1
>         except Exception as e:
>             # Handle other potential errors, though timeout is the one we expect
>             timeout_count += 1
>         finally:
>             sock.close()
> 
>         print_stats()
>         time.sleep(1)
> 
> except KeyboardInterrupt:
>     print("\n--- Test stopped. Final Statistics ---")
>     print_stats()
>     print("\n")
> 
> EOF
--- Starting DNS timeout test against 8.8.8.8 (Ctrl+C to stop) ---
Success: 68 | Timeouts: 0 | Total: 68 | Timeout Rate: 0.00%  ^C
--- Test stopped. Final Statistics ---
Success: 68 | Timeouts: 0 | Total: 68 | Timeout Rate: 0.00%