Network problem, duplicate packets


We are running into a problem running on a network with two QNX boxes. The
diagram is as follows:

[QNX1]-------(same Hub)------(same Switch)-------(same Router)---------[same

[QNX2]-------(same Hub)------(same Switch)-------(same Router)---------[same

There is a ethernet link between QNX1 and QNX2 in addition which carries
only layer 2 packets for updates and such.

This setup has worked fine for about two years until recently. There have
been some network changes which also included changing ip addresses on the
QNX boxes and now requires the connection to the remote machine to go
through the router described above. Before, the destination was on the
local LAN.

The QNX boxes will run fine for between 12 to 24 hours. Then at some point
we lose connectivity to the destination. If we do a ping to the
destination, we get the following pattern:

Ping Response time=12057 ms (DUP)
Ping Response time=11057 ms (DUP)
Ping Response time=10046 ms (DUP)
Ping Response time=9046 ms (DUP)
Ping Response time=8046 ms (DUP)
Ping Response time=7046 ms (DUP)
Ping Response time=6035 ms (DUP)
Ping Response time=5035 ms (DUP)
Ping Response time=4035 ms (DUP)
Ping Response time=3035 ms (DUP)
Ping Response time=2035 ms (DUP)
Ping Response time=1035 ms (DUP)
No response for about 5 seconds
Starts pattern over again

If we reset the network interface, the problem goes away until 12-24 hours
has elapsed. Has anyone ever seen behavior such as this? When the problem
exists, we cannot ping the QNX boxes from the router.

Thanks in advance!