- address (string list): IPv6 or IPv4 addresses to listen and send on
- port (integer): UDP port to listen and send on
+ address (string list): IPv6 or IPv4 addresses to listen and send on;
+ default is all local addresses
+ port (integer): UDP port to listen and send on; optional if you
+ don't need to have a stable address for your peers to talk to
+ (in which case your site ought probably to have `local-mobile true').