Sorry about the accidental discharge. As I was saying,

mono version 1.3b2 pc generic on new hardware
WAN:  a.b.c.34/27 fixed, gateway a.b.c.33
LAN:   10.1.0.1/16, dhcp server enabled
OPT1: bridged to WAN

LAN & OPT1 share a switch with 2 APs. All clients (~70) are wireless.
Most clients use dhcp, but some use a static IP on the a.b.c.32/27
network, thus routing through the OPT1 interface. DNS forwarder is
enabled.

Here's where I get confused. If I set my client router's WAN (being on
a wireless bridge to one of the above-mentioned APs) to automatic IP
address, I get a 10.1/16 address no problem. But then my connection to
the default route is intermittent.

During an "outage" I get no DNS, no ping response from 10.1.0.1 or any
other IP domain name or IP address. I can however release and renew my
IP address. These outages can last anywhere from a minute to several
hours.

Before you think this is a wireless issue, I repeat that I can
release/renew my IP address. I can confirm that my wireless bridge is
associated with the access point. I can actually associate with either
access point, these being on separate frequencies. All the usual signs
of radio interference are absent. Furthermore, I can assign my router
a static IP of a.b.c.43/27 gateway a.b.c.33 and no more outages. The
outages seem to be on the LAN subnet only.

I have tried this using 5 different routers on the client side, being
of 4 different makes (Linksysx2, D-Link, Trendnet, Soekris/monowall).
All identical symptoms. I tried 2 different wireless bridges on both
APs, no change.

I even gave my client router an alias on the WAN, using a.b.c.43/27
with a.b.c.33 as gateway, and 10.1.250.100 as alias, using 10.1.0.1 as
DNS server. I could simultaneously ping a.b.c.33 while getting no ping
or DNS response from 10.1.0.1.

Before you say my LAN card is shot, I can tell you that I have logged
into the monowall via it's WAN interface and seen traffic flowing
through the LAN, even while it would not respond to me on the LAN. So
the LAN card is not dead, it's apparently just practicing selective
ignorance.

So in summary, I've ruled out the client router, wireless bridge,
access point, and upstream provider as suspect. It appears to me that
it must be the monowall or the switch it is plugged into. But if
either of these is the case, then why is the OPT1 working flawlessly?
Why does the LAN work for some clients while simultaneously ignoring
others?

I should add that I haven't heard a single complaint from any of our
70 or so customers on this monowall. In fact, we have another monowall
with identical hardware and monowall version with 250 customers using
it, and no such complaint there.

The only possibly related complaint I am aware of is that some
customers are unable to get an address from monowall via dhcp and must
therefore use a static IP address, but this is relatively rare and
seems to be a different problem (one that is apparently exclusive to
Linksys clients, I might add).

Anybody care to hazard a guess as to what's going on here? I'm stumped
and I'm afraid it's going to start affecting other people.

Any insight appreciated.

db