Just wondering

Jared Mauch jared at puck.nether.net
Tue Apr 1 03:03:26 UTC 2014

On Mar 31, 2014, at 10:51 PM, Joe <jbfixurpc at gmail.com> wrote:

> Pardon for the ignorance regarding this. If folks can point me to something
> I may have missed as a participant for over 14 years, to powering this
> Alzheimers.
> I received several reports today regarding some scans for udp items from
> shadowservers hosted out of H.E. Seems to claim to be checking for issues
> regarding udp issues, amp issues, which I am all fine for, but my issue is
> this. It trips several IDP/IPS traps pretty much causing issues that I have
> to resolve. I have one user that is a home user (outside one of my /16)
> that has seen this as well. Now with that said are these folks that do this
> going to pay for one of my users that pay per bit for this? Does garbage in
> to this really provide a garbage clean? I see they are planing on a bunch
> of other protocols too, so that's nice.
> I'm not sure where to go with this other than to advise my other folks to
> drop this traffic from their networks and hope for the
> best regarding my FAP folks.

There are lots of people who think they need to monitor and respond to every
packet that they didn't "expect".

Sadly we are in a state of the world where these surveys have become necessary
both as part of people getting their PHD, but also to provide operational data
to network "first responders" in closing down Open Resolvers, NTP amplifiers
and many other resources that can be abused.

Many folks have automated tools that "complain" when these packets come at them
but aren't actually accurate in their complaints, like claiming the UDP packets
are an attempt to "log-in" to their service, or saying that UDP is TCP or something

There are a few people (Cymru, Shadowserver, myself via Open*Project) that are
doing work to enumerate and provide data on the problem to the community.

For each person that complains there's about 100 thank-yous for the data they

The R&E community have a number of criteria for their collection which is to have
rDNS and a website on a name matching that rDNS so people can visit it.

There are also lists of "do not probe" that exist:


If your security posture can't accept unsolicited packets you perhaps need to move to a whitelist model vs blacklist one for traffic.  (Or your policies about this need to be reviewed... I see every IP address I have control over either home or work get scanned by all sorts of malware and evil stuff, if you have to respond to each of them, that's an impractical task).

Without S.A.V.E. (BCP-38/84) one can't tell if that origin IP is accurate in any event.

- Jared

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