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We have BACnet system configured using ports 47811. While using wireshark for analysis, we found BACnet messages on port 47811 is not recognized.

asked 22 Jul '13, 04:39

RP_1985's gravatar image

accept rate: 0%

edited 22 Jul '13, 06:04

cmaynard's gravatar image

cmaynard ♦♦

Jasper is close, but the packets have to be UDP, and then you can select the BVLC (BACNet Virtual Link Control) protocol.

BVLC also has preferences for additional UDP ports, so you can add another port there so you don't need to "Decode As" for each new capture.

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answered 22 Jul '13, 05:22

grahamb's gravatar image

grahamb ♦
accept rate: 22%

I tried it on TCP and UDP, but didn't know about it being called "BVLC" :)

(22 Jul '13, 06:10) Jasper ♦♦

I had to look at the code to find out.

(22 Jul '13, 06:12) grahamb ♦

Thanks, grahamb,,,that's right...

(23 Jul '13, 21:59) RP_1985

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(23 Jul '13, 23:18) grahamb ♦

Usually I'd say you should try to use the popup menu on a packet that is not recognized and use the "Decode As" option to tell Wireshark how to decode the packet. But when I tested this I haven't seen anything called "BACnet", and it isn't listed in the protocol section of the preferences either. Maybe you can spot the correct protocol name though, in case it is not exactly called "BACnet".

Other than that it is possible that Wireshark does not decode your protocol at all, or have you seen it work on other ports?

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answered 22 Jul '13, 05:08

Jasper's gravatar image

Jasper ♦♦
accept rate: 18%

edited 22 Jul '13, 05:09

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question asked: 22 Jul '13, 04:39

question was seen: 5,842 times

last updated: 10 Mar '15, 14:22

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