igb message "Detected Tx Unit Hang" appears on a Red Hat Enterprise Linux 5 system

Issue

• The following message is seen in the logs, and the system is unreachable over the network :

  Sep 29 13:43:55 hostname kernel: igb 0000:0b:00.0: Detected Tx Unit Hang
  Sep 29 13:43:55 hostname kernel:   Tx Queue             <0>
  Sep 29 13:43:55 hostname kernel:   TDH                  <94>
  Sep 29 13:43:55 hostname kernel:   TDT                  <2e>
  Sep 29 13:43:55 hostname kernel:   next_to_use          <2e>
  Sep 29 13:43:55 hostname kernel:   next_to_clean        <92>
  Sep 29 13:43:55 hostname kernel: buffer_info[next_to_clean]
  Sep 29 13:43:55 hostname kernel:   time_stamp           <100448d89>
  Sep 29 13:43:55 hostname kernel:   next_to_watch        <93>
  Sep 29 13:43:55 hostname kernel:   jiffies              <100456c3b>
  Sep 29 13:43:55 hostname kernel:   desc.status          <328200>