Jeremy Begg - 2016-08-29

Hi,

I've tried to chase this up by reading earlier posts on this subject but I can't find the answer.

We wish to add BACnet support to a monitoring product which uses OpenWrt (an embedded Linux).

I have downloaded bacnet-stack 0.8.3 and built the demonstration programs including 'bacwi' and 'bacserv' under Ubuntu Linux 12.04. I have also successfully build the 'bacserv' program to run in our OpenWrt environment.

When I start 'bacserv' on OpenWrt it displays:

root@OpenWrt:~# bacserv 
BACnet Server Demo
BACnet Stack Version 0.8.3
BACnet Device ID: 260001
Max APDU: 1476

and a BACnet client running under Windows notices the I-Am broadcast from 'bacserv'.

However when I run 'bacwi' under Ubuntu Linux 12.04 it does not see 'bacserv' running under OpenWrt. It displays:

jeremy@devtest:~/bacnet-stack-0.8.3/bin$ ./bacwi 
;Device   MAC (hex)            SNET  SADR (hex)           APDU
;-------- -------------------- ----- -------------------- ----
;
; Total Devices: 0

What's really puzzling me is that tcpdump running on the same Linux host shows 'bacwi' sending out a UDP broadcast and 'bacserv' issuing a response:

13:29:16.973376 IP 10.1.200.202.47808 > 10.1.200.255.47808: UDP, length 12
    0x0000:  4500 0028 4fc5 4000 4011 4534 0a01 c8ca  E..(O.@.@.E4....
    0x0010:  0a01 c8ff bac0 bac0 0014 a5f1 810b 000c  ................
    0x0020:  0120 ffff 00ff 1008                      ........
13:29:16.974106 IP 10.1.200.50.47808 > 255.255.255.255.47808: UDP, length 25
    0x0000:  4500 0035 db7a 4000 4011 8d0a 0a01 c832  E..5.z@.@......2
    0x0010:  ffff ffff bac0 bac0 0021 fece 810b 0019  .........!......
    0x0020:  0120 ffff 00ff 1000 c402 03f7 a122 05c4  ............."..
    0x0030:  9103 2201 04                             .."..

What am I missing?

Thanks