I've been trying upgrading my TL-WR2543N from 17.01.6 to 18.06.1. I have a configuration with an IPv4-only connection to my ISP, so I'm running IPv6 on my lan via a HE.net tunnel. Which all works smoothly in 17.01.6 and previous.
With 18.06.1, all seems to be working, except I cannot ping between hosts on my LAN (plain single segment) when one is on wifi and the other wired. ping reports an error from the router 'Destination unreachable: Port unreachable'. As far as I can tell, the interfaces and routes are identical on the router, though it does grow an extra interface ifb1.
So far I've upgraded preserving settings. Before I try again but setting up 18.06 from scratch, is there anyone else using HE.net with 18.06 without this problem? Is setting up from scratch likely to cure the problem? Any suggestions on things to check?