samba - Jan 2016 - process_lanman_packet: Discarding datagram from IP 192.168.100.29. Source name STORAGE7<00> is one of our names !

Hi

I have a bunch of FreeNAS servers and a TrueNAS HA server all spamming 
the logs with these messages every minute about their own source name 
(examples below).

These boxes are on two physically separate networks, and I find it 
unlikely both networks should have some sort of undetected loop. Any 
ideas on how to debug this? Samba version is 4.1.18.

FreeNAS box on network A
"
Jan  5 23:17:43 storage7 nmbd[18901]: [2016/01/05 23:17:43.054231,  0] 
../source3/nmbd/nmbd_packets.c:1174(process_lanman_packet)
Jan  5 23:17:43 storage7 nmbd[18901]:   process_lanman_packet: 
Discarding datagram from IP 192.168.100.29. Source name STORAGE7<00> is 
one of our names !
"

TrueNAS active node network A
"
Jan  5 23:17:43 storage8 nmbd[21114]: [2016/01/05 23:17:43.052040,  0] 
../source3/nmbd/nmbd_packets.c:1174(process_lanman_packet)
Jan  5 23:17:43 storage8 nmbd[21114]:   process_lanman_packet: 
Discarding datagram from IP 192.168.100.36. Source name TRUENAS1<00> is 
one of our names !
"

FreeNAS box on network B
"
Jan  5 23:17:32 storage4 nmbd[34068]: [2016/01/05 23:17:32.086480,  0] 
../source3/nmbd/nmbd_packets.c:1174(process_lanman_packet)
Jan  5 23:17:32 storage4 nmbd[34068]:   process_lanman_packet: 
Discarding datagram from IP 172.21.140.17. Source name STORAGE4<00> is 
one of our names !
"

Thanks,

Torkil

On Tue, Jan 05, 2016 at 11:48:32PM +0100, Torkil Svensgaard
wrote:
> Hi
> 
> I have a bunch of FreeNAS servers and a TrueNAS HA server all
> spamming the logs with these messages every minute about their own
> source name (examples below).
> 
> These boxes are on two physically separate networks, and I find it
> unlikely both networks should have some sort of undetected loop. Any
> ideas on how to debug this? Samba version is 4.1.18.
> 
> FreeNAS box on network A
> "
> Jan  5 23:17:43 storage7 nmbd[18901]: [2016/01/05 23:17:43.054231,
> 0] ../source3/nmbd/nmbd_packets.c:1174(process_lanman_packet)
> Jan  5 23:17:43 storage7 nmbd[18901]:   process_lanman_packet:
> Discarding datagram from IP 192.168.100.29. Source name STORAGE7<00>
> is one of our names !
> "
> 
> TrueNAS active node network A
> "
> Jan  5 23:17:43 storage8 nmbd[21114]: [2016/01/05 23:17:43.052040,
> 0] ../source3/nmbd/nmbd_packets.c:1174(process_lanman_packet)
> Jan  5 23:17:43 storage8 nmbd[21114]:   process_lanman_packet:
> Discarding datagram from IP 192.168.100.36. Source name TRUENAS1<00>
> is one of our names !
> "
> 
> FreeNAS box on network B
> "
> Jan  5 23:17:32 storage4 nmbd[34068]: [2016/01/05 23:17:32.086480,
> 0] ../source3/nmbd/nmbd_packets.c:1174(process_lanman_packet)
> Jan  5 23:17:32 storage4 nmbd[34068]:   process_lanman_packet:
> Discarding datagram from IP 172.21.140.17. Source name STORAGE4<00>
> is one of our names !
> "
Are you forwarding broadcasts ? This is a debug level 0 log
coming from process_lanman_packet() telling you you have a
badly configured network :-).

You can fix the network, or recompile making the error
message a higher debug level than zero (which to be
honest is probably too low for this condition).

On 01/06/2016 01:23 AM, Jeremy Allison wrote:
>> Jan  5 23:17:32 storage4 nmbd[34068]: [2016/01/05 23:17:32.086480,
>> 0] ../source3/nmbd/nmbd_packets.c:1174(process_lanman_packet)
>> Jan  5 23:17:32 storage4 nmbd[34068]:   process_lanman_packet:
>> Discarding datagram from IP 172.21.140.17. Source name
STORAGE4<00>
>> is one of our names !
>> "
>
> Are you forwarding broadcasts ? This is a debug level 0 log
> coming from process_lanman_packet() telling you you have a
> badly configured network :-).
Is this typically a wiring/topology problem or could I have services on 
my network that forward broadcasts? Any suggestion on how to go about 
determining the source of potential forwards?

I have a wireshark capture of packets with contents in the few seconds 
around the error, anything in particular I could look for?

Thanks,

Torkil
-- 
Torkil Svensgaard
Sysadmin
MR-Forskningssektionen, afs. 714
DRCMR, Danish Research Centre for Magnetic Resonance
Hvidovre Hospital
Kettegård Allé 30
DK-2650 Hvidovre
Denmark
Tel: +45 386 22828
E-mail: torkil at drcmr.dk