UDLD禁用接口

Question

我们有两个思科c3850，它们是光纤端口10G的上行链路，我在那个中继(上行链路)端口上看到了这个错误。

[c3850]-----10G----[c3850]

TenGigabitEthernet1/1/4 is down, line protocol is down (err-disabled)

当我试图关闭/没有关闭端口时，我得到了以下错误

*May 26 10:12:02.506: %LINEPROTO-5-UPDOWN: Line protocol on Interface TenGigabitEthernet1/1/4, changed state to upsh int *May 26 10:12:04.405: %UDLD-4-UDLD_PORT_DISABLED: UDLD disabled interface Te1/1/4, unidirectional link detected *May 26 10:12:04.405: %PM-4-ERR_DISABLE: udld error detected on Te1/1/4, putting Te1/1/4 in err-disable state *May 26 10:12:05.409: %LINEPROTO-5-UPDOWN: Line protocol on Interface TenGigabitEthernet1/1/4, changed state to down *May 26 10:12:06.405: %LINK-3-UPDOWN: Interface TenGigabitEthernet1/1/4, changed state to down

什么是UDLD，为什么会引起这个问题。

上周，我们用最新的固件3.6.x升级了一个交换机，但仍然是运行在旧代码3.3.x上的第二个交换机。

你认为可能是版本错配问题吗？

更新

SW1

Interface Te1/1/4
---
Port enable administrative configuration setting: Follows device default
Port enable operational state: Enabled
Current bidirectional state: Unknown
Current operational state: Link down
Message interval: 7000 ms
Time out interval: 5000 ms

Port fast-hello configuration setting: Disabled
Port fast-hello interval: 0 ms
Port fast-hello operational state: Disabled
Neighbor fast-hello configuration setting: Disabled
Neighbor fast-hello interval: Unknown

No neighbor cache information stored

SW2

Interface Te1/1/4
---
Port enable administrative configuration setting: Follows device default
Port enable operational state: Enabled
Current bidirectional state: Unidirectional
Current operational state: Disabled port
Message interval: 7000 ms
Time out interval: 5000 ms

Port fast-hello configuration setting: Disabled
Port fast-hello interval: 0 ms
Port fast-hello operational state: Disabled
Neighbor fast-hello configuration setting: Disabled
Neighbor fast-hello interval: Unknown

No neighbor cache information stored

更新2

SW2#sh interfaces te1/1/4
TenGigabitEthernet1/1/4 is down, line protocol is down (err-disabled)
  Hardware is Ten Gigabit Ethernet, address is 6c99.8962.2938 (bia 6c99.8962.2938)
  Description: Connect_to_SW1
  MTU 1500 bytes, BW 10000000 Kbit/sec, DLY 10 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ARPA, loopback not set
  Keepalive not set
  Full-duplex, 10Gb/s, link type is auto, media type is SFP-10G-ACTIVE-CABLE
  input flow-control is off, output flow-control is unsupported
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input 3d04h, output never, output hang never
  Last clearing of "show interface" counters never
  Input queue: 0/2000/0/0 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: fifo
  Output queue: 0/40 (size/max)
  5 minute input rate 0 bits/sec, 0 packets/sec
  5 minute output rate 0 bits/sec, 0 packets/sec
     825762 packets input, 163952509 bytes, 0 no buffer
     Received 173 broadcasts (121 multicasts)
     0 runts, 0 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
     0 watchdog, 121 multicast, 0 pause input
     0 input packets with dribble condition detected
     362 packets output, 42206 bytes, 0 underruns
     0 output errors, 0 collisions, 3 interface resets
     0 unknown protocol drops
     0 babbles, 0 late collision, 0 deferred
     0 lost carrier, 0 no carrier, 0 pause output
     0 output buffer failures, 0 output buffers swapped out

SW1：

SW1#sh int te1/1/4
TenGigabitEthernet1/1/4 is down, line protocol is down (notconnect)
  Hardware is Ten Gigabit Ethernet, address is 6c99.8962.38b8 (bia 6c99.8962.38b8)
  Description: Connect_to_SW2
  MTU 1500 bytes, BW 10000000 Kbit/sec, DLY 10 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ARPA, loopback not set
  Keepalive not set
  Full-duplex, 10Gb/s, link type is auto, media type is SFP-10GBase-CX1
  input flow-control is off, output flow-control is unsupported
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input 3d04h, output never, output hang never
  Last clearing of "show interface" counters 2y4w
  Input queue: 0/2000/0/0 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: fifo
  Output queue: 0/40 (size/max)
  5 minute input rate 0 bits/sec, 0 packets/sec
  5 minute output rate 0 bits/sec, 0 packets/sec
     39504875093 packets input, 4530561503783 bytes, 0 no buffer
     Received 74817556 broadcasts (70452372 multicasts)
     0 runts, 0 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
     0 watchdog, 70452372 multicast, 0 pause input
     0 input packets with dribble condition detected
     5520672431 packets output, 1374955280906 bytes, 0 underruns
     0 output errors, 0 collisions, 0 interface resets
     0 unknown protocol drops
     0 babbles, 0 late collision, 0 deferred
     0 lost carrier, 0 no carrier, 0 pause output
     0 output buffer failures, 0 output buffers swapped out

更新：

与思科的支持，他们做了一些调试，但没有找到答案，我们更换了新的电缆，但没有运气。

但是一旦我们在界面上禁用了UDLD，接口就会出现。一旦启用UDLD接口，就会进入错误禁用模式。

思科TAC这可能是生成树循环，真的吗？UDLD在物理层上运行，生成树如何阻止或禁用该端口？

Answer 1

解决方案：

我们有两个开关。

[SW1]------10G------[SW2]

我们用最新版本升级了SW1，升级后UDLD在两个交换机之间失败。

我们在那个端口上禁用了UDLD，所有的工作文件数据都在双向链接上流动。

后来在SW2升级开关与最新和最伟大的软件解决了所有问题，我们重新启用的UDLD和所有的好。

Answer 2

这个文档关于UDLD (UniDirectional链接检测)将是一个很好的评论。

UDLD检测到，在启动端口之前，双方都可以接收数据包，而不仅仅是物理连接。因此，假设您已经验证了没有布线问题，交叉跳线等，那么这是一个配置设置。

很可能，您在一个交换机上启用了UDLD，而没有启用另一个交换机。

试着从两边的show udld开始进行故障排除。

Answer 3

它可能不是UDLD而是生成树。一旦处于错误禁用状态，清除out，关闭两个接口，设置

switchport mode trunk
switchport trunk encapsulation dot1

然后打开两个接口。