Hi

In one of customer installations on 6.3.0SP3 after some time EN1 interface drops offline (not actually offline, but 
loses all communications) while EN0 remains still operational. After rebooting everything works well again. Both 
interfaces are integrated on motherboard and are handled by a single io-net process. Is there a way to tell for sure 
what's happening there (if it's a hardware or software fault)?

The machine is kept running, so that I'll be able to request for additional info on Monday if necessary. Here's 
something to start with.

--------------------------
The symptoms are the same before: EN1 stops responding to both TCP/IP and QNET.  EN0 is still active and functioning.  I
 was able to grab the following info for you:

# nicinfo /dev/io-net/en1
INTEL 82544 Gigabit (Copper) Ethernet Controller
 
  Physical Node ID ........................... 003048 B037CB
  Current Physical Node ID ................... 003048 B037CB
  Current Operation Rate ..................... 100.00 Mb/s full-duplex
  Active Interface Type ...................... MII
    Active PHY address ....................... 0
  Maximum Transmittable data Unit ............ 1514
  Maximum Receivable data Unit ............... 0
  Hardware Interrupt ......................... 0xb
  Memory Aperture ............................ 0xd0200000 - 0xd021ffff
  Promiscuous Mode ........................... Off
  Multicast Support .......................... Enabled
 
  Packets Transmitted OK ..................... 16489506
  Bytes Transmitted OK ....................... 1550295660
  Broadcast Packets Transmitted OK ........... 27233
  Multicast Packets Transmitted OK ........... 0
  Memory Allocation Failures on Transmit ..... 0
 
  Packets Received OK ........................ 16603917
  Bytes Received OK .......................... 1545543297
  Broadcast Packets Received OK .............. 57710
  Multicast Packets Received OK .............. 0
  Memory Allocation Failures on Receive ...... 0
 
  Single Collisions on Transmit .............. 0
  Deferred Transmits ......................... 7
  Late Collision on Transmit errors .......... 0
  Transmits aborted (excessive collisions) ... 0
  No Carrier on Transmit ..................... 0
  Receive Alignment errors ................... 0
  Received packets with CRC errors ........... 0
  Packets Dropped on receive ................. 11905
#
 
# /sbin/ifconfig
lo0: flags=8009<UP,LOOPBACK,MULTICAST> mtu 33212
        capabilities=7<IP4CSUM,TCP4CSUM,UDP4CSUM>
        enabled=0<>
        inet 127.0.0.1 netmask 0xff000000
en0: flags=8c43<UP,BROADCAST,RUNNING,OACTIVE,SIMPLEX,MULTICAST> mtu 1500
        capabilities=7<IP4CSUM,TCP4CSUM,UDP4CSUM>
        enabled=0<>
        address: 00:30:48:b0:37:ca
        inet 192.168.1.70 netmask 0xffffff00 broadcast 192.168.1.255
en1: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
        capabilities=7<IP4CSUM,TCP4CSUM,UDP4CSUM>
        enabled=0<>
        address: 00:30:48:b0:37:cb
        inet 192.168.10.44 netmask 0xffffff00 broadcast 192.168.10.255
#
 
# pci
 
PCI version    = 3.00
 
Class          = Display (VGA)
Vendor ID      = 8086h, Intel Corporation
Device ID      = 2972h,  Integrated Graphics Controller
PCI index      = 0h
PCI Mem Address = d0000000h enabled
PCI Mem Address = c0000000h enabled
PCI IO Address  = 30c0h enabled
PCI Int Pin    = INT A
Interrupt line = 10
CPU Interrupt  = ah
 
Class          = Mass Storage (IDE)
Vendor ID      = 8086h, Intel Corporation
Device ID      = 27c0h,  82801GB/GR/GH (ICH7 Family) Serial ATA Storage Controller IDE
PCI index      = 0h
PCI IO Address  = 0h enabled
PCI IO Address  = 0h enabled
PCI IO Address  = 0h enabled
PCI IO Address  = 0h enabled
PCI IO Address  = 30b0h enabled
PCI Mem Address = ffeffc00h enabled
PCI Int Pin    = INT B
Interrupt line = no connection
 
Class          = Network...