hadiasghari / pyasn

Python IP address to Autonomous System Number lookup module. (Supports fast local lookups, and historical lookups using archived BGP dumps.)
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Private IPs in database files #74

Open EugeniuZ opened 2 years ago

EugeniuZ commented 2 years ago

Hi,

Currently I see these entries in the database file:

; IP-ASN32-DAT file
; Original source: rib.20220413.1800.bz2
; Converted on  : Wed Apr 13 19:48:48 2022
; Prefixes-v4   : 963212
; Prefixes-v6   : 152468
...
192.168.1.0/24  141011
192.168.2.0/24  141011
192.168.3.0/24  141011
192.168.7.0/24  141011
...

Could you please clarify why are private IP ranges assigned an ASN?

EugeniuZ commented 2 years ago

At least it should not map to public ASNs.

hadiasghari commented 2 years ago

Hi @EugeniuZ ,

This isn't normally the case. It seems like an error with the MRT/RIB/BGP data. A simple fix would be to filter out these private ranges from the file. Where did you download your RIB file from?

EugeniuZ commented 2 years ago

Hi @hadiasghari ,

This is what I see in the log:

Finding most recent archive in /route-views4/bgpdata/2022.04/RIBS ...
Downloading ftp://archive.routeviews.org//route-views4/bgpdata/2022.04/RIBS/rib.20220414.0600.bz2

We're using the provided tool to download the database (pyasn_util_download.py --latestv46)

So is this the wrong place to report the issue?

hadiasghari commented 2 years ago

@EugeniuZ, I am not spending much time on this project at the moment, so I cannot unfortunately debug this issue at the moment. Basically, pyasn parses the RIB file information to produce its ipasn.dat file. The RIB file is a dump from a router's BGP table (in this case from route-views4 vantage). These private v4 addresses should not appear in the RIB files--and typically don't. Perhaps this is some temporary problem with this vantage point? I'd recommend downloading a couple of recent RIB files from other vantage points (you can find them via a search), and converting those too to see if the private IP range appear in them too. That should help narrow the problem cause.... I hope this helps.