nanog mailing list archives
Re: PlayStationNetwork blocking of CGNAT public addresses
From: Rich Kulawiec <rsk () gsp org>
Date: Sun, 18 Sep 2016 09:07:03 -0400
On Sun, Sep 18, 2016 at 01:30:52PM +0100, Tom Smyth wrote:
2)do some "canary in the mine" monitoring for obviously malicious traffic (loads of SMTP traffic outbound) and lots of connection requests to SSH servers ... if you see that traffic from behind your CGNAT device .. just temporarily block the internal ip of the user until they clean up their devices.
Seconded. This is something I've recommended for years (decades, I suppose by now). Simple measurements of what's "normal" for your operation in terms of connection rates, types, etc., are easy to make. That in turn enables measurements of what's abnormal and that in turn enables manual or automatic actions. For example: if the average number of outbound SSH connections established per hour per host across all hosts behind CGNAT is 3.2, and you see a host making 1100/hour: that's a problem. It might be someone who botched a Perl script; or it might be a botted host trying to brute-force its way into something. These kinds of measurements are relatively easy to make and don't require invading user privacy. They won't catch everything, of course, but they're not intended to. They may catch enough to solve the problem in front of you at the moment *and*, if they do that, they may reduce the scope/scale of the rest of the problems to make them more tractable via other techniques. ---rsk
Current thread:
- Re: PlayStationNetwork blocking of CGNAT public addresses, (continued)
- Re: PlayStationNetwork blocking of CGNAT public addresses Mike Hammett (Sep 16)
- Re: PlayStationNetwork blocking of CGNAT public addresses Roland Dobbins (Sep 16)
- Re: PlayStationNetwork blocking of CGNAT public addresses Simon Lockhart (Sep 16)
- Re: PlayStationNetwork blocking of CGNAT public addresses Roland Dobbins (Sep 16)
- RE: PlayStationNetwork blocking of CGNAT public addresses michalis.bersimis (Sep 16)
- Re: PlayStationNetwork blocking of CGNAT public addresses Simon Lockhart (Sep 16)
- Re: PlayStationNetwork blocking of CGNAT public addresses A . L . M . Buxey (Sep 16)
- Re: PlayStationNetwork blocking of CGNAT public addresses Ca By (Sep 16)
- RE: PlayStationNetwork blocking of CGNAT public addresses Tony Wicks (Sep 16)
- Re: PlayStationNetwork blocking of CGNAT public addresses Masataka Ohta (Sep 16)
- Re: PlayStationNetwork blocking of CGNAT public addresses Tom Smyth (Sep 18)
- Re: PlayStationNetwork blocking of CGNAT public addresses Rich Kulawiec (Sep 18)
- Re: PlayStationNetwork blocking of CGNAT public addresses Florian Weimer (Sep 18)
- Re: PlayStationNetwork blocking of CGNAT public addresses Rich Kulawiec (Sep 19)
- Re: PlayStationNetwork blocking of CGNAT public addresses Florian Weimer (Sep 19)
- Re: PlayStationNetwork blocking of CGNAT public addresses Rich Kulawiec (Sep 23)
- Re: PlayStationNetwork blocking of CGNAT public addresses Rich Kulawiec (Sep 18)
- Re: PlayStationNetwork blocking of CGNAT public addresses Mike Hammett (Sep 18)
- Re: PlayStationNetwork blocking of CGNAT public addresses Florian Weimer (Sep 18)
- Re: PlayStationNetwork blocking of CGNAT public addresses Simon Lockhart (Sep 18)
- Re: PlayStationNetwork blocking of CGNAT public addresses Florian Weimer (Sep 18)
- Re: PlayStationNetwork blocking of CGNAT public addresses Simon Lockhart (Sep 18)