After configuring tunnel server and selecting "Start Tunnel", the tunnel does not start. The "Server Status" is still "Stopped". Running "netstat -an" shows no processes listening on tunnel port (48003).
The hub robot only has an IPv6 address.
The hub.log file shows entries similar to the following:
Jul 11 11:43:03:105 [139892907120448] 4 hub: nimSockaddr2Ip - found ####:####:####:####:####:####:####:####
Jul 11 11:43:03:105 [139892907120448] 2 hub: nimIP2Ether - rc=1 (error), ip='####:####:####:####:####:####:####:####'
Jul 11 11:43:03:105 [139892907120448] 2 hub: nimVerifyLogin warning, could not obtain ether from ip='####:####:####:####:####:####:####:####'
As of 20.4 CU8, this requires an enhancement. Development has created this new feature to be added (F137383 - Tunnel support between hubs in ipv6 environment).