Re: Intermittent incorrect DNS resolution?

Erik Levinson erik.levinson at
Fri Jan 18 01:42:58 UTC 2013

Thanks Damian. I see four requests with Google UAs from actual Google IPs, and (PTR and rwhois seem yours for both), in a period of 30 minutes (compared to over 80 per minute on the new IPs). This is pretty low, so I'm not too worried. 

Baidu is the main culprit now; there's little other traffic. In fact, we're getting no traffic from Baidu on the new IPs, only to the old ones. I've already e-mailed their spider help e-mail, but it's fallen on deaf ears.


-----Original Message-----
From: "Damian Menscher" <damian at>
Sent: Thursday, January 17, 2013 1:58pm
To: "Erik Levinson" <erik.levinson at>
Cc: "NANOG mailing list" <nanog at>
Subject: Re: Intermittent incorrect DNS resolution?

On Wed, Jan 16, 2013 at 8:09 PM, Erik Levinson
<erik.levinson at>wrote:

> To give an idea of the scale of the problem right now, I'm getting
> thousands of requests per minute to a new IP vs. about two requests per
> minute on the equivalent old IP, with over 60% of the latter being Baidu,
> but also a bit of Googlebot and other random bot and non-bot UAs.

It's common for malware to spoof the Googlebot user-agent since they know
most webmasters won't block it.  You might want to check whether the IPs
you're seeing it from are really allocated to us -- if so, I'd be
interested in tracking down why we're crawling your old IP.


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