The Source column is used to describe how a hub is connected to other hubs -- essentially it can be thought of as displaying the "next hop"?of a hub-to-hub connection, and can help you whether a hub needs to "pass through" any other hubs to communicate with a particular destination hub.
One way to look at it is that the "Source" column answers the question, "How does the current hub know about another hub?"
If the Source column shows the local IP address of the hub that you're looking at, instead of another hub's name, that indicates that the two hubs in question are directly connected via a tunnel. ?The IP/port combination shown in "Source" in this case will reflect the local port that is being used to handle the?tunnel connection.
Otherwise, the Source column will either be empty, or contain another hub's name.
In the above example screenshot, we can see that there are several hubs in this environment. ? Those which have a blank "Source" column are directly connected to the current hub -- meaning that they are on the same local network and can communicate directly without the need for tunnels or proxy hubs. ?Therefore, the "Source" of this connection is the local hub itself - this hub "knows about" those other hubs because it can connect directly to them (and they to it.)
For the hub which is highlighted, Customer_Hub_001, we can see that another hub's name - Proxy_hub - ?is shown in the Source column; this indicates that the current hub cannot directly connect to Customer_Hub_001, but it "knows about" Customer_Hub_001 because the hub called Proxy_Hub has shared that information with our current hub. ? So, if the current hub communicates with Customer_Hub_001, that communication would be routed through Proxy_Hub.
?The (1) in parentheses indicates that the Customer_Hub_001 is "one hop" away from Proxy_hub. ? If there were another hub, perhaps called Customer_Hub_002, that was a tunnel client to Customer_Hub_001, then we would see Customer_Hub_002 with a "Source" of Proxy_hub, but with (2) instead, indicating that Customer_Hub_002 is actually 2 hops away -- the "Source" column only displays the next hop in the chain.
In such a scenario, if you were to look at the GUI on Proxy_Hub, you would see Customer_Hub_002 with the "Source" column displaying "Customer_Hub_001 (1)".