For the convenience of Synchronet Sysops:
Not sure if your BBS's TCP/IP ports are open to the Internet? Not sure what your public IP address currently is? From your BBS computer, go to this web-page and enter the password, 'sbbs': http://vert.synchro.net/scanmyports.ssjs
Since Vertrauen is only IPv4 at the moment, so is this scanning page. :-)
I know there are many very similar tools on the Internet (e.g. canyouseeme.org), but this one is tuned specifically for Synchronet sysops and checks all the common Synchronet TCP/IP sevices.
Synchronet "Real Fact" #6:
Synchronet version 3 for Linux and FreeBSD development began in 2001.
Norco, CA WX: 66.3°F, 77.0% humidity, 3 mph SE wind, 0.00 inches rain/24hrs