nanog mailing list archives

Re: Probes from root servers


From: bmanning () vacation karoshi com
Date: Fri, 17 Jul 2009 19:07:24 +0000

On Thu, Jul 16, 2009 at 03:56:29PM -0700, Pederson, Krishna wrote:
One of our IP addresses is being probed by up to 8 of the 13 root dns servers every 15 seconds. I'm looking for input 
on how to contact the admins for the servers or perhaps a way to figure out if perhaps someone is spoofing the 
affected customer IP address, causing the root servers to send the following:

sh mls netflow ip destination 74.1.32.205 /32 module 2
Displaying Netflow entries in module 2
DstIP           SrcIP           Prot:SrcPort:DstPort  Src i/f          :AdjPtr
-----------------------------------------------------------------------------
Pkts         Bytes         Age   LastSeen  Attributes
---------------------------------------------------
74.1.32.205     193.0.14.129    udp :dns    :1039     Fa2/11           :0x0
0            0             1     22:49:03   L3 - Dynamic
74.1.32.205     202.12.27.33    udp :dns    :1039     Fa2/11           :0x0
0            0             2     22:49:03   L3 - Dynamic
74.1.32.205     192.36.148.17   udp :dns    :1039     Fa2/11           :0x0
0            0             2     22:49:03   L3 - Dynamic


Is it practical to attempt to work the issue with the root server admins or is it quite likely this is spoofing and 
there's no hope to track this down?

Thanks,
Kris


        i feel confident that you have received one or more private replies, but since 
        this is a recurent complaint, it may be worth the post.

        Root nameservers do not gratuitously send traffic. They respond to queries
        they receive.  based on the information above, 74.1.32.205 has sent a query
        to the roots and they are responding as they should.

        if this is unwanted/undesired, you need to look at the source of the query,
        not the site responding to the request for information.  the root server ops
        will have no way to evaluate if the packets they receive are spoofed.

        one way to contact the root server operators is via email:
                
                        comments () root-servers org

--bill
        


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