DDOS, IDS, RTBH, and Rate limiting

Denys Fedoryshchenko denys at visp.net.lb
Fri Nov 21 17:06:54 UTC 2014

On 2014-11-21 18:41, Peter Phaal wrote:
>>> Actually, sFlow from many vendors is pretty good (per your points 
>>> about
>>> flow
>>> burstiness and delays), and is good enough for dDoS detection.  Not 
>>> for
>>> security forensics, or billing at 99.99% accuracy, but good enough 
>>> for
>>> traffic visibility, peering analytics, and (d)DoS detection.
>> Well, if it is available, except hardware limitations, there is second
>> obstacle,
>> software licensing cost. On latest JunOS, for example on EX2200, you 
>> need
>> to purchase license (EFL), and if am not wrong it is $3000 for 48port 
>> units.
>> So if only sFlow feature is on stake, it worth to think, to purchase
>> license,
>> or to purchase server.
> Juniper no longer charges for sFlow on the EX2200 (as of Junos 11.2):
> http://www.juniper.net/techpubs/en_US/junos11.2/information-products/topic-collections/release-notes/11.2/junos-release-notes-11.2.pdf
> I am not aware of any vendor requiring an additional license to enable 
> sFlow.
> sFlow (packet sampling) works extremely well for the DDoS flood
> detection / mitigation use case. The measurements are build into low
> cost commodity switch hardware and can be enabled operationally
> without adversely impacting switch performance.  A flood attack
> generates high packet rates and sampling a 10G port at 1-in-10,000
> will reliably detect flood attacks within seconds.
> For most use cases, it is much less expensive to use switches to
> perform measurement than to attach taps / mirror port probes. If your
> switches don't already support sFlow, you can buy a 10G capable white
> box switch for a few thousand dollars that will let you monitor 1.2
> Terabits/sec. If you go with an open platform such as Cumulus Linux,
> you could even run your DDoS mitigation software on the switch and
> dispense with the external server. Embedded instrumentation is simple
> to deploy and reduces operational complexity and cost when compared to
> add on probe solutions.
> Peter Phaal
> InMon Corp.
Wow, that's great news then, i'm using mostly Cisco gear now, but seems 
will have to take a look to Juniper, thanks for information.
If it is free, then if EX2200 available, it is much easier to run sFlow 
and write custom collector for it, than installing custom probe(in most 
common cases).

Best regards,

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