My servers have become part of the no-reply count in the multiplayer list. I've run most of them for a couple of years now with this exact setup, but since a week or two ago they've not shown up in the multiplayer list. If I try to connect directly by name they time out. (I have DCON excluded from AV and firewall shield and have tried with those both disabled also.)

I suspected a problem with ports/forwarding so I changed all the ports and added new rules, now one will connect (PiranMOTORaceOfChampions) but not the rest. I've checked all the ports, UDP and TCP, from a website and they're reported open, and each check shows up in the relevant DCON with 'Accept: <IP>'. They all show up in the LFSW host list, LFSRemote can connect so packets can get through.

But, when I try to connect directly I see 'connecting to host' on the client and 'Guest wants to join' on the DCON but it doesn't then show an 'Accept: <IP>', and I get 'connect timed out' or 'clientconnect: connect failed' on the client. That would suggest that DCON isn't receiving the request that the client sends directly to the host (as directed by the master server), but why not if the ports are open and working?

I can't think what to do next to solve this, any suggestions?

Edit: Also upgraded to T3, both client and DCON.

Quote from THE WIZARD DK :

perhaps this makes sense then : https://www.lfs.net/forum/post/1946034#post1946034

its now T4

There were no changes between T3 and T4 DCON, AFAIK. Wizard, please, as Scawen said, don't post that often. Please.

PiranMOTO servers live again

I didn't solve the problem, but I did find a way around it. Early on, one of the things I tried was moving the port range. This worked, but only for the first port in the range, none of the others. Today I thought to try putting each one on a port that wasn't part of a range, separated a bit in number, having its own port-forwarding rule.

That's done the trick, although it doesn't help me work out why it broke in the first place

But, it's worth adding to the list of things-to-try when servers don't respond