Since the protocol is UDP I wouldn't be too surprised if effective sender is using multiple hosts to send UDP Data. So in fact, what you're doing, is just fighting the symptoms and not the desease. I have certain doubts that subxtreme.net is the real origin.

I myself am experiencing an abnormal amount of UDP Queries to this port as well - although the rate is much lower than at your site (about 20'000/min).

On May 30, 2008, at 6:20 PM, Marco Fretz wrote:

Hi everybody,

is there anyone else expecting massive UDP (mostly port 53) traffic from
67.228.4.81? Destinations are (possibly random chosen) ip address out of
our AS3915.

see attached netflow graph. We've now blocked the ip address and got
over 3.7 million blocks within 10 minutes.

I just wrote this issue to the corresponding abuse (abuse@subxtreme.net)
, a provider in Brazil as i know so far.

Thanks for any feedback.

have a nice weekend, best regards
Marco

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