Added 3rd NIC to server, can't use 3rd NIC for NAT

[Jeff Powell]

I have a W2k server with 3 NICs in it. Two are 3Com 3C90x cards. One has a
local IP and the other has a public IP. I have routing enabled. I was
using these to do NAT for the local net but found that the NAT blocked
packets coming from the public DMZ net to the local net. So I added a third
NIC, an old ISA NE2000 card. I gave this a public address and filled in all
the appropriate info-- IP, subnet, gateway, and DNS. I set it up exactly as
if it were the primary external NIC.
The card does function; I can ssh into the server from my Linux box.
But when I set this up as the public interface in NAT, I get no Internet
access from the local net.
The idea is that I want to use this as the public NAT address so that other
servers on the DMZ net can use the other public IP on the server (the
non-NAT address) to route back to the local net. When I delete the NAT NIC
from NAT and add the other public NIC instead, Internet access on the local
end works fine. But when I use the NAT NIC, no access.
Anyone know what I'm doing wrong?

Thanks,

Jeff

 

[Jeff Powell]

Got it partially working. Something to do with the binding order again.
However, this time I have to disable the Public NIC and re-enable it. What
order should I put the binding order in? I have 3 NICS-- 1 public NIC which
is the Internet "face" of the server (for mail, web, etc). A private NIC
for the local net. And, a second public NIC used only for NAT.

Plus, when I disable the public NIC and re-enable it to make the NAT work, I
get an error about there being a duplicate name on the network (same error
when re-enabling the NAT NIC). What up with that? And I can't seem to stop
Windows from adding DNS records for all three IP's held by the server. I
want DNS to have only one A record, the public IP and not the NAT address or
the local IP.

Thanks,

Jeff

 

[Jeff Powell]

Yet more info.
After I reboot, when I disable and then re-enable the public NIC, the NAT
starts working but I can't ping hosts on the local net from the public net.
If I then disable and re-enable the NAT NIC, I can ping hosts on the local
net but I lose NAT.

Argh!

 

[Alan Wood [MSFT]]

Hi Jeff,
Built in Windows 2000 NAT was not designed to function with 3 NIC's.
You maybe able to get it to work by enabling disabling and changing binding
order but in reality it just was not designed to work this way, so it may
never work properly.
Maybe if you explian more on what you are trying to accomplish we could
help you get it work in a supported by design configuration.

Thanks!

Alan Wood[MSFT]

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