Hi Peter,
thanks for all your suggestions. They were really helpful in bringing me to the solution of the problem.
- "netstat -an" - to make sure stunnel is listening on the correct
interface and port
This was OK.
- does "lastcomm stunnel' show anything useful? If you don't use threads a new stunnel process starts with each connection.
This showed nothing useful.
- just a guess but remove the socket entries in the config file - maybe they are causing a problem. I don't use them but maybe there is a
good reason to use them.
The socket entries were there because they were in the original config file which I edited for my purposes. They seemed ok to me so I left them in my config when I began experimenting with stunnel. Commenting them out didn't make any difference for this problem.
- try connecting directly to the stunnel box (no router). does that
always work
Maybe not always, but remarkably better!!!
- maybe the NIC card is flaky
The card had worked just fine until then, so I didn't really believe in this. I thought I'd save this for the last.
- run "stunnel -version" to verify all is configured as you think.
Seems all right.
So what the heck could the problem be. It took me a long time to figure out the answer. The fact that almost all connection attempts succeeded when the router was left out of the picture would suggest there was a problem with the router configurations. But no, the router was correctly configured. Instead, the routing tables of the linux work station were not right! That's a problem I've hardly ever had to deal with (and therefore a subject I don't understand enough of) so it took some experimenting to get the routing tables right. Now it looks good. I still can't explain why the original routing tables sometimes worked and sometimes didn't, but I'll study the subject :-)
Tommi