Here is my physical set up.
I am sitting in my office. To access the internet, a packet from my
computer has to go onto our private wan using a 172.16.(0 or 1).XXX subnet
and mask. The packet goes through a switch (unmanaged) and
down the hall to a 5.8MHz radio. It is beamed to our middle school 9
miles awaybto another 5.8 radio. From there it goes into a switch where
the cables from the two radios that blanket the buildings in our district
converge (all still on private 172 subnet). This switch is connected to a
media converter to fiber and the fiber runs the length of the building to
a server room (400 feet, or so).

In the server room it goes into another media converter back to CAT5 (both
same brand converter, both set to autosense) and into another unmanaged
switch. This switch then connects to the private side nic of our Border
Manager box and the private side nic of an IPCop box. Both on the same
172 subnet. Which one a packets goes to depends on the proxy settings of
the machine originating the packet.

The packet gets processed (or ignored in my case as the admin workstation
has no proxy filtering) and comes out of the public side nic of one of
those two boxes. These have public IP Addresses given to us by our ISP
( The public side of each box goes into the same switch
(which is different from the private side switch). Out of that switch and
into a cat5 to fiber media converter, down the hall, through another media
converter and directly into the ISP's 5.8 radio that beams the signal off
to their router someplace in Effingham, Illinois

Occassionly, we (district wide) loses our connection to the Inernet. When
I lose my connection to the Internet I can ping the radios on our wan and
the private side nic of the IPCop box and BM box. But I can't ping
through to the public nic of either of them or to the ISPs radio or router

The biggest mystery I have is why it is intermittent. If it was simply a
configuration issue then it seems like I would have no connection ever. I
can't think of an external (power?) issue that would have an affect at
this point of failure. I could see it affecting the ability to get
through a switch or media converter, or radio, but how could it affect the
traffic INSIDE the box itself?

This is really quite frustrating!