I have an IPCop installation with red-orange-green networks.
I have been getting a number of rx errors on the green interface. As I understand it, that means on data coming from the green zone (and presumably heading for the red zone).

eth0 Link encap:Ethernet HWaddr 00:0E:2E:B8:AC:B1
inet addr:192.168.0.254 Bcast:192.168.0.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:544420 errors:142 dropped:0 overruns:0 frame:0
TX packets:754435 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:53901007 (51.4 MB) TX bytes:252286301 (240.5 MB)
Interrupt:9 Base address:0xb000

What causes this?
Is it a problem on the green network itself?
Does anyone have a good reference for the error types on ifconfig output?

They do not seem to be at a very high level, but I would like to understand it better.
My first reaction was to try another NIC. That didn't fix it

So what's it mean then?

I've got several ipcops running a net to net VPN in addition to standard firewall duties but have never seen this amount of errors.

Prime suspect is your internal network - cabling, switchs etc

Yes, that was my assumption. Thanks for the info. I will start swapping out some switches and cables.