I have a jtac case on this, but just incase anyone have had the same problem.
When we try to excecute commands on the device (we have accessed it with ssh blah@1.1.1.1 -s netconf), the srx closes the connection. Normal ssh works so its seems to be something on the srx.
It looks like this when i try to excecute to commands.
<rpc><get-system-information/></rpc><rpc><close-session/></rpc> debug1: client_input_channel_req: channel 0 rtype exit-status reply 0
debug1: channel 0: free: client-session, nchannels 1
Transferred: sent 1784, received 4280 bytes, in 5.4 seconds
Bytes per second: sent 332.3, received 797.3
debug1: Exit status 0
debug3: Wrote 192 bytes for a total of 1981
debug3: Wrote 112 bytes for a total of 2093
debug3: Wrote 96 bytes for a total of 2189
debug3: Wrote 96 bytes for a total of 2285
debug3: Wrote 80 bytes for a total of 2365
debug3: Wrote 64 bytes for a total of 2429
<!-- No zombies were killed during the creation of this user interface -->
<!-- user root, class super-user -->
<hello>
<capabilities>
<capability>urn:ietf
arams:xml:ns:netconf:base:1.0</capability>

<capability>urn:ietf
arams:xml:ns:netconf:capability:candidate:1.0</capabil ity>

<capability>urn:ietf
arams:xml:ns:netconf:capability:confirmed-commit:1.0</ capability>

<capability>urn:ietf
arams:xml:ns:netconf:capability:validate:1.0</capabili ty>

<capability>urn:ietf
arams:xml:ns:netconf:capability:url:1.0?protocol=http, ftp,file</capability>

<capability>http://xml.juniper.net/netconf/junos/1.0</capability>
<capability>http://xml.juniper.net/dmi/system/1.0</capability>
</capabilities>
<session-id>25649</session-id>
</hello>
]]>]]> debug1: client_input_channel_req: channel 0 rtype exit-status reply 0
debug2: channel 0: rcvd eow
debug2: channel 0: close_read
debug2: channel 0: input open -> closed
debug2: channel 0: rcvd eof
debug2: channel 0: output open -> drain
debug2: channel 0: obuf empty
debug2: channel 0: close_write
debug2: channel 0: output drain -> closed
debug2: channel 0: rcvd close
debug3: channel 0: will not send data after close
debug2: channel 0: almost dead
debug2: channel 0: gc: notify user
debug2: channel 0: gc: user detached
debug2: channel 0: send close
debug2: channel 0: is dead
debug2: channel 0: garbage collecting
debug1: channel 0: free: client-session, nchannels 1
debug3: channel 0: status: The following connections are open:
#0 client-session (t4 r0 i3/0 o3/0 fd -1/-1 cfd -1)
debug3: channel 0: close_fds r -1 w -1 e 6 c -1
debug3: Wrote 32 bytes for a total of 2461
debug3: Wrote 64 bytes for a total of 2525
Transferred: sent 2232, received 4600 bytes, in 2.1 seconds
Bytes per second: sent 1076.7, received 2219.1
debug1: Exit status 0
^
So here it closes the connectioln
To compare with other devices
debug2: subsystem request accepted on channel 0
<!-- No zombies were killed during the creation of this user interface -->
<!-- user remote, class j-shb-admins -->
<hello>
<capabilities>
<capability>urn:ietf
arams:xml:ns:netconf:base:1.0</capability>

<capability>urn:ietf
arams:xml:ns:netconf:capability:candidate:1.0</capability>

<capability>urn:ietf
arams:xml:ns:netconf:capability:confirmed-commit:1.0</capability>

<capability>urn:ietf
arams:xml:ns:netconf:capability:validate:1.0</capability>

<capability>urn:ietf
arams:xml:ns:netconf:capability:url:1.0?protocol=http,ftp,file</capability>

<capability>http://xml.juniper.net/netconf/junos/1.0</capability>
<capability>http://xml.juniper.net/dmi/system/1.0</capability>
</capabilities>
<session-id>57470</session-id>
</hello>
]]>]]>
<rpc><get-system-information/></rpc><rpc><close-session/></rpc>
debug3: Wrote 112 bytes for a total of 1901
<rpc-reply xmlns="urn:ietf
arams:xml:ns:netconf:base:1.0" xmlns:junos="http://xml.juniper.net/junos/12.1X44/junos">

<system-information>
<hardware-model>srx1400</hardware-model>
<os-name>junos-es</os-name>
debug1: client_input_channel_req: channel 0 rtype exit-status reply 0
debug2: channel 0: rcvd eow
debug2: channel 0: close_read
debug2: channel 0: input open -> closed
<os-version>12.1X44-D50.2</os-version>
<serial-number>BBBBBBB</serial-number>
<host-name>fw-layer9-backup.hej.ru</host-name>
<cluster-node/>
</system-information>
</rpc-reply>
]]>]]>
<rpc-reply xmlns="urn:ietf
arams:xml:ns:netconf:base:1.0" xmlns:junos="http://xml.juniper.net/junos/12.1X44/junos">

<ok/>
</rpc-reply>
]]>]]>
<!-- session end at 2016-12-29 13:25:35 CET -->
Becouse of this, i cant add this device in junos space.
Anyone have had this problem?