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Re: Thank you, Comcast.


From: "Roland Dobbins" <rdobbins () arbor net>
Date: Fri, 26 Feb 2016 23:51:57 +0700

On 26 Feb 2016, at 23:44, Blake Hudson wrote:

Jason, how do you propose to block SSDP without also blocking legitimate traffic as well (since SSDP uses a port > 1024 and is used as part of the ephemeral port range on some devices) ?

I'm not Jason, but blocking specific port-pairs such as UDP/80 ---> UDP/1900 and UDP/443 ---> UDP/1900 solves close to 90% of the problem, as UDP/80 and UDP/443 are the most common destination ports leveraged in this type of attack.

For an explanation of how UDP reflection/amplification attacks work, see this .pdf preso:

<https://app.box.com/s/r7an1moswtc7ce58f8gg>

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Roland Dobbins <rdobbins () arbor net>


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