[AusNOG] 188.8.131.52 Bogon Update
Martin - StudioCoast
martin.sinclair at studiocoast.com.au
Thu Aug 25 19:02:57 EST 2011
Below is a basically summary of the steps involved, rest assured its not
for the faint hearted and I lost a couple of weeks working on it!
Inspired by http://www.anchor.com.au/blog/2009/05/testing-your-connectivity/
1. Retrieve a copy of the full routing table (I used
2. Wrote a vb.net program to extract the first subnet for each ASN.
For example our subnet appears as:
* 184.108.40.206/22 220.127.116.11 0 0 0 8492 3356
24130 24473 24473 i
The ASN we use is 24473
3. Once I had the subnet list (approximately 38000 entries) I wrote
another program to ping the first 50 ip addresses of every subnet on my
ADSL connection trying to find a pingable address.
Using multithreading and a 1mbit upload, this took around a couple of hours.
4. The final list of 28000 entries is on our website
http://www.studiocoast.com.au/downloads/asn-reach-test.txt (as always,
use at own risk)
The test was completed last weekend from an Internode ADSL connection,
many of the IP addresses may no longer be reachable.
5. The final list was then pinged simultanously from both 18.104.22.168/22
and another debogoned range on the same network.
6. The result was about 400 ASNs that could not be accessed. I then used
the various IP whois servers to retrieve the technical email contacts
and send them an email requesting the prefix be de-bogoned.
Only around 250 ASNs had contact emails that I could find.
In the email I referenced http://www.ris.ripe.net/cgi-bin/debogon.cgi,
Cymru and the IETF draft.
7. Around 120 ASNs responded and fixed their filters.
On 25/08/2011 12:15 PM, Martin - StudioCoast wrote:
> Just thought I would let everyone know that the bogon filtering issues
> on the 22.214.171.124 block are now resolved amongst australian isps.
> As far as I can tell, visibility is 100% in Australia now that Three
> have removed their filter.
> I have also completed an ASN scan of the greater internet (all 38000
> of them!) and identified 300 ASNs that may be blocking the prefix.
> Each ASN owner was contacted and so far 130 or so have removed the filter.
> If anbody would like some further information on how the tests were
> conducted let me know.
> Martin Sinclair
> AusNOG mailing list
> AusNOG at lists.ausnog.net
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