Cisco ASA：显示界面上的“ tx挂起”计数器是什么？

考虑以下输出show interface：

Interface GigabitEthernet0/1 "inside", is up, line protocol is up
  Hardware is i82546GB rev03, BW 1000 Mbps, DLY 10 usec
    Full-Duplex(Full-duplex), 1000 Mbps(1000 Mbps)
    Input flow control is unsupported, output flow control is off
    MAC address 5057.aaaa.25d7, MTU 1500
    IP address 10.0.0.7, subnet mask 255.255.255.0
    2708954646 packets input, 1614638330819 bytes, 0 no buffer
    Received 786860 broadcasts, 0 runts, 0 giants
    7262 input errors, 7262 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
    0 pause input, 0 resume input
    0 L2 decode drops
    2622997029 packets output, 1295347863682 bytes, 6396 underruns
    0 pause output, 0 resume output
    0 output errors, 0 collisions, 90 interface resets
    0 late collisions, 0 deferred
    0 input reset drops, 7908 output reset drops, 31 tx hangs

最后一行说31 tx hangs。这是什么意思？

挂起通常是指“花费太长时间”导致控制器或接口复位的以太网帧传输。不过，“花太长时间”的意思有点神秘。