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Date:      Tue, 3 Sep 2013 18:58:00 -0700
From:      Kurt Buff <kurt.buff@gmail.com>
To:        freebsd-net@freebsd.org
Subject:   Re: Question regarding security run output
Message-ID:  <CADy1Ce4EnnrfU9DjneHTf1J=%2BFPD7ihQKbP3Tbf3zB3PuMHQnQ@mail.gmail.com>
In-Reply-To: <20130904000959.GG19904@verio.net>
References:  <CADy1Ce5b-fHNK3FELMnZtzYnQw6jwYgczVF5DUE1CPnE4EfZCg@mail.gmail.com> <20130904000959.GG19904@verio.net>

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On Tue, Sep 3, 2013 at 5:09 PM, David DeSimone <fox@verio.net> wrote:
> Kurt Buff <kurt.buff@gmail.com> wrote:
>>
>> Over the three-day US weekend, I was working on some stuff, and found an
>> interesting set of entries in the daily security run emails all three days.
>>
>> The output looks as follows:
>>
>> ntop.example.com kernel log messages:
>>
>> +++ /tmp/security.IUGsscCR       2013-08-26 03:02:24.000000000 -0700
>>
>> +arp: unknown hardware address format (0x4500) (from 00:05:b7:de:cd:79 to
>> 72:6e:61:6c:2c:70)
>>
>> +arp: unknown hardware address format (0x0100) (from 00:05:b7:de:cd:79 to
>> 6c:3d:31:37:2c:6e)
>>
>> +arp: unknown hardware address format (0x4500) (from 00:05:b7:de:cd:a3 to
>> 77:72:69:74:74:65)
>>
>> +arp: unknown hardware address format (0x0000) (from 00:05:b7:de:cd:71 to
>> 2d:0d:0a:62:6f:64)
>
> These are all interesting because the destination MAC address is
> composed entirely of valid ASCII characters.
>
>     72:6e:61:6c:2c:70 = "rnal,p"
>
>     6c:3d:31:37:2c:6e = "l=17,n"
>
>     77:72:69:74:74:65 = "writte"
>
>     2d:0d:0a:62:6f:64 = "-\r\nbod"

That is indeed interesting.

>> This box is monitoring a mirror port on a procurve switch, using an
>> unnumbered interface.
>>
>> My investigation led me to the engineering lab, and I'm querying them
>> regarding the equipment, but I don't know what the above entries signal.
>> Does anyone have a clue they can throw me on this?
>>
>> I also find it interesting that the MAC addresses are either unknown, or
>> belong to Arbor Networks. We don't have any Arbor Networks equipment,
>> though I suppose they could vend them to an OEM. I'm going to see if I can
>> trace them down and get some idea of what's running around in that lab.
>
>
> Is there some hardware NIC fault causing DMA from random places in
> memory on these devices, or some other data leak propogating through the
> stack on them?  It is probably worth capturing the odd packets and
> analyzing them further to see why they look the way they do.

Unknown, but the units in that lab are a system/product under
development, and after talking with them this afternoon, they did
mention they were having some problems. I shall pass your tidbits on
to them, and see if it rings a bell for them.

Many thanks for the help.

Kurt



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