user56377: I have a bitcoin-core node running on a Raspberry Pi on my local network.   The node is publically visible and running fine (I can see it on bitnodes.21.co - it has connections and is synced to the latest block).
I have a Windows PC with a Bitcoin-Qt installation that I would like to connect only to the local node, only when I start it up it doesn't seem to connect. I'm starting it from a command line with 
bitcoin-qt.exe -connect 192.168.0.6
The GUI just says "Connecting to peers" and Help > Debug shows 0 connections.
I can ping the Pi from the Windows machine and I can telnet to port 8333 on the Pi from the Windows machine, so I believe the network connectivity isn't the issue.
Any advice on how to diagnose what's going on? (RPC commands? Logs?)  
Am I using the right command to connect?

user43738: It might be you need to add some lines in the bitcoin.conf file on the Raspberry Pi.  This was taken from the github repo example of the bitcoin.conf file
##############################################################
##            Quick Primer on addnode vs connect            ##
##  Let's say for instance you use addnode=4.2.2.4          ##
##  addnode will connect you to and tell you about the      ##
##    nodes connected to 4.2.2.4.  In addition it will tell ##
##    the other nodes connected to it that you exist so     ##
##    they can connect to you.                              ##
##  connect will not do the above when you 'connect' to it. ##
##    It will *only* connect you to 4.2.2.4 and no one else.##
##                                                          ##
##  So if you're behind a firewall, or have other problems  ##
##  finding nodes, add some using 'addnode'.                ##
##                                                          ##
##  If you want to stay private, use 'connect' to only      ##
##  connect to "trusted" nodes.                             ##
##                                                          ##
##  If you run multiple nodes on a LAN, there's no need for ##
##  all of them to open lots of connections.  Instead       ##
##  'connect' them all to one node that is port forwarded   ##
##  and has lots of connections.                            ##
##       Thanks goes to [Noodle] on Freenode.               ##
##############################################################

# Use as many addnode= settings as you like to connect to specific peers
#addnode=69.164.218.197
#addnode=10.0.0.2:8333

# Alternatively use as many connect= settings as you like to connect ONLY to specific peers
#connect=69.164.218.197
#connect=10.0.0.1:8333

# Listening mode, enabled by default except when 'connect' is being used
#listen=1

# Maximum number of inbound+outbound connections.
#maxconnections=

#
# JSON-RPC options (for controlling a running Bitcoin/bitcoind process)
#

# server=1 tells Bitcoin-Qt and bitcoind to accept JSON-RPC commands
#server=0


56377: <p>I have a bitcoin-core node running on a Raspberry Pi on my local network.   The node is publically visible and running fine (I can see it on bitnodes.21.co - it has connections and is synced to the latest block).</p>

<p>I have a Windows PC with a Bitcoin-Qt installation that I would like to connect only to the local node, only when I start it up it doesn't seem to connect. I'm starting it from a command line with </p>

<p><code>bitcoin-qt.exe -connect 192.168.0.6</code></p>

<p>The GUI just says "Connecting to peers" and Help > Debug shows 0 connections.</p>

<p>I can ping the Pi from the Windows machine and I can telnet to port 8333 on the Pi from the Windows machine, so I believe the network connectivity isn't the issue.</p>

<p>Any advice on how to diagnose what's going on? (RPC commands? Logs?)  </p>

<p>Am I using the right command to connect?</p>
 43738: <p>It might be you need to add some lines in the bitcoin.conf file on the Raspberry Pi.  This was taken from the <a href="https://github.com/bitcoin/bitcoin/blob/master/contrib/debian/examples/bitcoin.conf" rel="nofollow noreferrer">github repo example of the bitcoin.conf file</a></p>

<pre><code>##############################################################
##            Quick Primer on addnode vs connect            ##
##  Let's say for instance you use addnode=4.2.2.4          ##
##  addnode will connect you to and tell you about the      ##
##    nodes connected to 4.2.2.4.  In addition it will tell ##
##    the other nodes connected to it that you exist so     ##
##    they can connect to you.                              ##
##  connect will not do the above when you 'connect' to it. ##
##    It will *only* connect you to 4.2.2.4 and no one else.##
##                                                          ##
##  So if you're behind a firewall, or have other problems  ##
##  finding nodes, add some using 'addnode'.                ##
##                                                          ##
##  If you want to stay private, use 'connect' to only      ##
##  connect to "trusted" nodes.                             ##
##                                                          ##
##  If you run multiple nodes on a LAN, there's no need for ##
##  all of them to open lots of connections.  Instead       ##
##  'connect' them all to one node that is port forwarded   ##
##  and has lots of connections.                            ##
##       Thanks goes to [Noodle] on Freenode.               ##
##############################################################

# Use as many addnode= settings as you like to connect to specific peers
#addnode=69.164.218.197
#addnode=10.0.0.2:8333

# Alternatively use as many connect= settings as you like to connect ONLY to specific peers
#connect=69.164.218.197
#connect=10.0.0.1:8333

# Listening mode, enabled by default except when 'connect' is being used
#listen=1

# Maximum number of inbound+outbound connections.
#maxconnections=

#
# JSON-RPC options (for controlling a running Bitcoin/bitcoind process)
#

# server=1 tells Bitcoin-Qt and bitcoind to accept JSON-RPC commands
#server=0
</code></pre>
