The "Internet" settings control the connectivity for whois, update checks, etc.
Right-clicking a hop on the upper "route" graph on any hop that has a DNS name defined gives us the option of looking up that name and seeing who the owner is. We use the "Whois" protocol for this, and we talk to the server specified here. Default: whois.crsnic.net
Internet IP Addresses are assigned ownership, and sometimes its interesting to find out who owns them. This is the server that does this for us – default: whois.arin.net
PingPlotter can check with the PingPlotter servers occasionally to see if there’s a new version available. This can be done automatically, or it can be done manually by hitting the "Check Now" button.
The Proxy Setup is currently used for only one thing – doing the version check. PingPlotter doesn’t use these settings to do the trace in any way.