KDE Connect problem

[Timothy Murphy]

I'm trying to use KDE Connect to transfer files
from my Samsung Galaxy S5 phone running Android 5.0
to my Lenovo T510 Fedora-23/KDE laptop

This occasionally works, but not usually
and not at this moment.

First I click on KDE Connect on my laptop.
This lists my phone, and when I click on the phone icon
I'm told it is paired.

But when I click on KDE Connect on my phone,
my laptop is listed but underneath it says
"This paired device is not reachable.
Make sure it is connected to your same network."

I can ping the phone from the laptop,
and I can ping the laptop from the phone, using PingTools.
I have opened ports 1714-1764 TCP and PDP on the laptop
(which is running firewalld) with firewall-config.
netstat -atun shows (among other entries)
[tim at william ~]$ sudo netstat -atun
tcp        0      0 0.0.0.0:22              0.0.0.0:*               LISTEN     
tcp6       0      0 :::1714                 :::*                    LISTEN     
udp        0      0 0.0.0.0:67              0.0.0.0:*                          
udp6       0      0 :::1714                 :::*                               

(I'm not sure whey 1714 is listed as tcp6 and udp6 ?)

I'm running CentOS-7 on my home server with shorewall.
In /etc/shorewall/policy I have
loc             $FW             ACCEPT
$FW             loc             ACCEPT

Any suggestions or advice gratefully received.

-- 
Timothy Murphy  
gayleard /at/ eircom.net
School of Mathematics, Trinity College, Dublin