Hi all,
i'm attempting to connect a slave jack running on windows 7 64bit and a jack master running on linux ubuntu studio 14.04 64bit.
jack is verified to be 1.9.10 on both sides. 
firewall is also completely open between windows and linux.
the 2 ends can ping each other - no problem

jack master is running on alsa and with netjack2 also running. other linux pc's connect without a problem to this jack master. 

but jack slave running from windows does not show up on master jack... what can I assume is wrong?
mtu have not been tampered with.

jack slave on windows states:
C:\Program Files (x86)\Jack>jackd.exe -dnet  -i2 -o9 -C8 -p8
jackdmp 1.9.10
Copyright 2001-2005 Paul Davis and others.
Copyright 2004-2014 Grame.
jackdmp comes with ABSOLUTELY NO WARRANTY
This is free software, and you are welcome to redistribute it
under certain conditions; see the file COPYING for details
Drivers/internals found in : C:\Windows
Drivers/internals found in : C:\Windows
JACK server starting in realtime mode with priority 10
self-connect-mode is "Don't restrict self connect requests"
InitTime : multimedia timer resolution set to 1 milliseconds
MMCSS API not used...
NetDriver started in async mode without Master's transport sync.
Waiting for a master...

and here is the same running it with verbose output :
http://pastebin.com/KZTRLigc

I am using 'tcpdump' on the jack master to listen for udp packets on port 19000 (where jack broadcasts by default). the cmd is:
tcpdump host <ip_of_jackd_client> and udp port 19000
In turn I checked some linux clients and the windows client:

linux cl1 (ip 192.168.112.133 - name jackcl1)
16:10:39.532802 IP jackcl1.19000 > jack_master.58548: UDP, length 44
16:10:39.533960 IP jack_master.58548 > jackcl1.19000: UDP, length 1500
16:10:39.533970 IP jack_master.58548 > jackcl1.19000: UDP, length 204

linux client 2 (ip 192.168.112.144 - name jackcl2) looks similar
16:23:09.842778 IP jackcl2.19000 > jack_master.54735: UDP, length 204
16:23:09.842782 IP jackcl2.19000 > jack_master.54735: UDP, length 564
16:23:09.843880 IP jack_master.54735 > jackcl2.19000: UDP, length 1500
16:23:09.843890 IP jack_master.54735 > jackcl2.19000: UDP, length 204


unfortunately it looks like the windows jack client sends out the packets, but the jack master never responds...
16:11:52.040582 IP wincl1.19000 > jack_master.19000: UDP, length 644
16:11:53.528440 IP wincl1.19000 > jack_master.19000: UDP, length 644
16:11:55.028455 IP wincl1.19000 > jack_master.19000: UDP, length 644

can you make anything out of that?

thank you in advance for your help.