aslookup
Python client for IP to ASN lookup services
aslookup is a client utility for two of the public IP/AS query services
operated by the following organizations:
The client implements both a simple Python module (aslookup) as well as a CLI
utility (as-lookup
). The lookups are currently done using DNS, which works
well for a one-off lookups. It is not optimized for bulk lookups over the
Whois protocol.
Currently only IPv4 addresses are looked up. The client also maintains a
listing of IP networks which are unroutable internet addresses, typically
special use ranges in RFCs. In this way it can both filter out addresses from
queries which are a waste of time, as well as provide context to the user on
the address.
Installation
The app has been tested on Python 3.
It's best to install the program into a Python virtualenv. If you will only use
the command line interface, the recommended way to install it is using
pipx:
pipx install aslookup
If you will use aslookup as a library, you'll instead want to install it using
pip
in your target Python environment:
python3 -m pip install aslookup
Usage
Python module
The Python module defaults to querying the Team Cymru data service. The
desired service may be specified by passing the service parameter to
get_as_data
.
from aslookup import get_as_data
ip = "8.8.8.8"
get_as_data(ip, service="shadowserver")
CLI script
It is possible to provide multiple IP addresses as arguments to the script, or
to send them as a list on standard input, in which cases the script loops over
them and returns output on separate lines. When providing invalid IPv4
addresses as arguments, the script reports the problem on standard error and
exits with an error. When providing input on stdin, the error is reported on
standard output but execution is not aborted.
as-lookup 8.8.8.8 9.9.9.9
or:
as-lookup < ipaddrs.txt
Test data
A list of test values for the script is included in the file tests/test_input.txt
.
This can be useful to validate included IP prefix classifications and see the
output format.
as-lookup < tests/test_input.txt