I'm not sure if this is a bug or intentional, but I have noticed that when
ppp0 dies (due to disconnect - deliberate or otherwise), all the TCP
connections are also lost. I have moved back to the kernel which does not
have this problem.

This is the one I moved back to.
NetBSD 1.6T (FOREST) #0: Tue Jun 10 03:32:44 BST 2003

and this is the one that has the different behaviour
NetBSD 1.6U (FOREST) #5: Wed Jul 30 17:13:21 BST 2003

CVS updates were done on the day of the build I believe.

If it is not a bug, is there a kernel option?

Richard Smith