3rd nic's a charm?

[Tim Pushor]

Hi all, happy holidays!

I have an old box that I am using as my home firewall/NAT box for my 
residential cable ISP. It was running at or about 4.0.

I was using 2 xl interfaces (3com 3c509b's) and was very stable.

I have recently added another network at home, and wanted to add another 
interface to the box, so I added another 509b and the box became 
unstable. It would work, then hang, then work etc. The thing just 
rebooted itself a few minutes ago.

I installed 5.1-RELEASE on it for a couple of reasons, but was curious 
to see if I tickled a bug in the stack or driver by adding the 3rd nic. 
The box doesn't exhibit the exact same problems now, but still stops 
responding to network traffic once in a while. (i.e its still unstable, 
but the symptoms are different).

I am pretty sure the card I put in is OK - it came from a working 
system. The box is of an older vintage - Its a P133 with an Intel VX 
chipset on a gigabyte motherboard.

After a while last night, dmesg reported weird things, like just one 
garbled line.

The relevant bits from a working dmesg:
xl0: <3Com 3c905B-TX Fast Etherlink XL> port 0x6100-0x617f mem 
0xe4002000-0xe400207f irq 11 at device 8.0 on pci0
xl0: Ethernet address: 00:10:5a:12:89:1e
miibus0: <MII bus> on xl0
xlphy0: <3Com internal media interface> on miibus0
xlphy0:  10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, auto
xl1: <3Com 3c905B-TX Fast Etherlink XL> port 0x6200-0x627f mem 
0xe4000000-0xe400007f irq 10 at device 9.0 on pci0
xl1: Ethernet address: 00:50:04:67:7e:63
miibus1: <MII bus> on xl1
xlphy1: <3Com internal media interface> on miibus1
xlphy1:  10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, auto
xl2: <3Com 3c905B-TX Fast Etherlink XL> port 0x6300-0x637f mem 
0xe4001000-0xe400107f irq 9 at device 10.0 on pci0
xl2: Ethernet address: 00:10:5a:07:21:43
miibus2: <MII bus> on xl2
xlphy2: <3Com internal media interface> on miibus2
xlphy2:  10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, auto

Any ideas?

Thanks!
Tim