Display the list of CIDRs

list-cidr-by-asn.py

import re
import subprocess

ASN = "AS200373"

cmd = f"whois -h whois.radb.net -- '-i origin {ASN}'"

result = subprocess.run(
    cmd,
    shell=True,
    capture_output=True,
    text=True,
    check=True,
)

cidrs = set()

for line in result.stdout.splitlines():
    line = line.strip()

    m = re.match(r"^route:\s+(.+)$", line)
    if m:
        cidr = m.group(1)
        cidrs.add(cidr)

    # m = re.match(r"^route6:\s+(.+)$", line)
    # if m:
    #     cidr = m.group(1)

    #     # Exclude huge IPv6 ranges such as /29
    #     try:
    #         net = ipaddress.ip_network(cidr)

    #         # Exclude prefixes smaller than /32 (e.g., /31, /29)
    #         if net.prefixlen < 32:
    #             continue

    #     except ValueError:
    #         continue

    #     cidrs.add(cidr)

for cidr in sorted(cidrs):
    print(cidr)