I have my NetBSD system hooked up to the net with a 24x7 PPP link.
Once in a while, the PPP line appears to go dead, though the modem
stays connected.  More precisely, if I attempt an outgoing ping, I
see the transmit light flash but get no response; an incoming ping
from another location results in no activity at all.  I recently
turned on LCP ECHO packets, and these get responses, but IP traffic
is entirely dead.  Hanging up the modem and redialing restores the
connection.

Has anyone else seen this?  I'll bet long odds that it's a router
problem, given the evidence, but I wanted to make sure this isn't
some known NetBSD bug that just hasn't been mentioned.

Thanks,
John Woods, jfw@funhouse.com