Re: [tor-relays] OVH Mitigation

2020-09-10 Thread Ben Tasker
On Thu, Sep 10, 2020 at 8:48 AM Dr Gerard Bulger 
wrote:

> I know we should dilute our dependence on OVH, but cheap and seem to
> ignore the fact the machine is an exit node.
>
>
>
> OVH has a seemingly patented a system to deal with denial of service
> attacks.  I am not sure what they detect but when they do we get this:
>
>
>
> *“We have just detected an attack on IP address x.x.x.x.  In order to
> protect your infrastructure, we vacuumed up your traffic onto our
> mitigation infrastructure. The entire attack will thus be filtered by our
> infrastructure, and only legitimate traffic will reach your servers. At the
> end of the attack, your infrastructure will be immediately withdrawn from
> the mitigation”*
>
>
>
I have a server (not a relay) with OVH, and also started receiving these
recently. I raised a ticket with them to ask for more information about the
detected attack (what port/proto etc) because there are legitimate uses
that may look a bit like an attack (the boxes sit behind a CDN, so you can
end up with a lot of requests/connections from not may IPs)

Worryingly, they couldn't actually tell me - all I managed to get back was
"looks like it's a false positive". It's triggered a few times since, with
no sign of anything even remotely suspicious in my traffic graphs.

I know this doesn't really add much knowledge about what they're detecting,
but the point is more that they don't seem to be overly clear themselves


-- 
Ben Tasker
https://www.bentasker.co.uk
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Re: [tor-relays] OVH Mitigation

2020-09-10 Thread Roger Dingledine
On Wed, Sep 09, 2020 at 12:00:37PM +0100, Dr Gerard Bulger wrote:
> To be fair, the automated system takes it off after an our or two.  If my
> tor server is left in this mitigated state, the tor exit gets labelled a BAD
> EXIT which is something to avoid as takes days to be trusted again.

Can you point us to which relay this happened to, and an approximate
timestamp?

We don't badexit that many relays these days, so I am wondering if
something else is going on instead.

Thanks,
--Roger

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[tor-relays] OVH Mitigation

2020-09-10 Thread Dr Gerard Bulger
I know we should dilute our dependence on OVH, but cheap and seem to ignore
the fact the machine is an exit node.

 

OVH has a seemingly patented a system to deal with denial of service
attacks.  I am not sure what they detect but when they do we get this:

 

"We have just detected an attack on IP address x.x.x.x.  In order to protect
your infrastructure, we vacuumed up your traffic onto our mitigation
infrastructure. The entire attack will thus be filtered by our
infrastructure, and only legitimate traffic will reach your servers. At the
end of the attack, your infrastructure will be immediately withdrawn from
the mitigation"

 

To be fair, the automated system takes it off after an our or two.  If my
tor server is left in this mitigated state, the tor exit gets labelled a BAD
EXIT which is something to avoid as takes days to be trusted again.   As
soon as I get their email I now stop TOR to prevent that embarrassing label,
and perhaps doing so stops whatever it is OVH is detecting.  Being shutdown
for a few hours seems better than being a bad exit.

 

Gerry

 

 

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