nanog mailing list archives

Re: Getting hit hard by CHINANET


From: Colin Johnston <colinj () gt86car org uk>
Date: Mon, 23 Mar 2015 13:19:04 +0000

China network blocks work great, I wish did not have to use but they never respond to admin or abuse contacts either

Colin


On 23 Mar 2015, at 13:06, Ray Soucy <rps () maine edu> wrote:

I did a test on my personal server of filtering every IP network assigned
to China for a few months and over 90% of SSH attempts and other noise just
went away.  It was pretty remarkable.

Working for a public university I can't block China outright, but there are
times it has been tempting. :-)

The majority of DDOS attacks I see are sourced from addresses in the US,
though (likely spoofed).  Just saw a pretty large one last week which was
SSDP 1900 to UDP port 80, 50K+ unique host addresses involved.


On Wed, Mar 18, 2015 at 8:32 AM, Eric Rogers <ecrogers () precisionds com>
wrote:

We are using Mikrotik for a BGP blackhole server that collects BOGONs
from CYMRU and we also have our servers (web, email, etc.) use fail2ban
to add a bad IP to the Mikrotik.  We then use BGP on all our core
routers to null route those IPs.

The ban-time is for a few days, and totally dynamic, so it isn't a
permanent ban.  Seems to have cut down on the attempts considerably.

Eric Rogers
PDSConnect
www.pdsconnect.me
(317) 831-3000 x200


-----Original Message-----
From: NANOG [mailto:nanog-bounces () nanog org] On Behalf Of Roland Dobbins
Sent: Wednesday, March 18, 2015 6:04 AM
To: nanog () nanog org
Subject: Re: Getting hit hard by CHINANET


On 18 Mar 2015, at 17:00, Roland Dobbins wrote:

This is not an optimal approach, and most providers are unlikely to
engage in such behavior due to its potential negative impact (I'm
assuming you mean via S/RTBH and/or flowspec).

Here's one counterexample:

<https://ripe68.ripe.net/presentations/176-RIPE68_JSnijders_DDoS_Damage_
Control.pdf>

-----------------------------------
Roland Dobbins <rdobbins () arbor net>




-- 
Ray Patrick Soucy
Network Engineer
University of Maine System

T: 207-561-3526
F: 207-561-3531

MaineREN, Maine's Research and Education Network
www.maineren.net


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