What is the mean "%STP-2-DISPUTE_DETECTED" ?

[syjeon]

Hi.

We test the Nexus as daisy chain.

but When we attach the port to port in the same module, We got the following log :

"%STP-2-DISPUTE_DETECTED"

I had searched the log on CCO, but I can't find exactly what mean is.

If you know the log, Please let me know as soon as possibly

Thanks in advance.

[Jon Marshall]

syjeon wrote:
Hi.
We test the Nexus as daisy chain.
but When we attach the port to port in the same module, We got the following log :
"%STP-2-DISPUTE_DETECTED"
I had searched the log on CCO, but I can't find exactly what mean is.
If you know the log, Please let me know as soon as possibly
Thanks in advance.

Error message -

1. %STP-2-DISPUTE_DETECTED: Dispute detected on port [chars] on [chars]. The spanning tree has detected a Dispute on this interface. The BPDU received from  the peer is Inferior with designated role and state as     learning and/or forwarding. Since this  condition could be caused by an     unidirectional link failure, the interface is put into blocking state  and marked as disputed in order to prevent possible loops from being created.

Recommended Action: Issue the show spanning-tree inconsistentports command to review the list  of interfaces with Dispute. Dispute is caused if the peer in not receiving the Superior BPDUs sent  by this interface. That is why the peer continues to send its own Inferior BPDUs. Determine why  devices connected to the listed ports are not receiving BPDUs. One reason could be a failure in the  cable: if the link has a failure that makes it unidirectional (you can not transmit but you can receive)  it should be replaced with a proper cable.

Related documents- No specific documents apply to this error message.

Jon

[Krzysztof Zaleski]

Hello,

I just wanter to refresh this issue. I understand the reason of dispute on a certain link, but recently I had a situation where dispute appeared on all links attached to N7K. There are two reasons I can think of. One is some kind of bug/instability on the N7K itself. Two, there was some STP inconsistency in the network, however all links are rather edge switches. This could point to some vPC issue, where one peer still sends superior BPDU, and the other does not (bug?).

Cheers,

Krzysztof

[habadr]

Hi

This is related to new feature called Spanning tree dispute mechanism in NX-OS and 6500 starting 12.2(33)SXI. The following link has more details anout it in Nexus 7K running NX-OS 4.2.

http://www.cisco.com/en/US/docs/switches/datacenter/sw/4_2/nx-os/layer2/configuration/guide/Cisco_Nexus_7000_Series_NX-OS_Layer_2_Switching_Configuration_Guide_Release_4.2_chapter6.html#con_1490082

Thanks

Hatim Badr

[poz]

I had this issue recently and spent some time troubleshooting the fiber link only to find out the far end switch, a 3750 did not include the native VLAN command on the trunk interface. Normally when that command is missing you get a native VLAN mismatch syslog error but not in this case on either side.

Symptom: Nexus 7000 %STP-2-DISPUTE_DETECTED: Dispute detected on port Ethernet3/21 on VLAN0100

(config-if)# sh spanning-tree blockedports

Name                 Blocked Interfaces List

-------------------- ------------------------------------

VLAN0100             Eth3/21

Finally cleared - %STP-2-DISPUTE_CLEARED: Dispute resolved for port Ethernet3/21 on VLAN0100.

We had native VLAN configured on the 7K side but not the 3750, added switchport trunk native vlan 100.

I wanted to reply so if anyone has this issue they can look into the native VLAN as all the documentation I found mentions unidirectional link failure as cause. This is not always the case.

[ปลาวาฬทราย RMUTT CPE IX]

I found more than 50 vlans DISPUTE_DETECTED and DISPUTE_CLEARED within 3 seconds. How should I do?

Thank you very much.

[n-kirillov]

Hi!

You need to investigate network link to this interface. In my case on my Nexus port I have not cisco device in STP 802.1D mode, but which have Cisoc devices behind him in RPVSTP mode, and I can't find which one send inferior bpdu (

2020 Aug 27 15:57:50 SW.NEXUS.CORE.2 %STP-2-DISPUTE_CLEARED: Dispute resolved for port Ethernet1/13 on VLAN0044.
2020 Aug 27 15:57:50 SW.NEXUS.CORE.2 %STP-2-DISPUTE_DETECTED: Dispute detected on port Ethernet1/13 on VLAN0044.
2020 Aug 27 15:57:51 SW.NEXUS.CORE.2 %STP-2-DISPUTE_CLEARED: Dispute resolved for port Ethernet1/13 on VLAN0044.
2020 Aug 27 15:57:51 SW.NEXUS.CORE.2 %STP-2-DISPUTE_DETECTED: Dispute detected on port Ethernet1/13 on VLAN0044.
2020 Aug 27 15:57:53 SW.NEXUS.CORE.2 %STP-2-DISPUTE_CLEARED: Dispute resolved for port Ethernet1/13 on VLAN0044.
2020 Aug 27 15:57:53 SW.NEXUS.CORE.2 %STP-2-DISPUTE_DETECTED: Dispute detected on port Ethernet1/13 on VLAN0044.

[hwang4]

I experienced the same issue when upgrading Nexus 7K.  Anyone has thoughts on why this happened?

Thanks.

[Georg Pauwen]

Hello,

STP disputes usually arise from a non-root switch not receiving a superior BPDU from the root switch, and sending a SBPDU to the neighboring switch itself, indicating itself is the root switch. That creates a conflict and causes the interface to be STP blocked, until the dispute is resolved.

Post the output of:

show spanning-tree summary interface type slot/port detail

for the port in question.

[zhijqiu]

The high probability of ‘STP disputes‘ is caused by the single-pass of the line. His principle is that when a sub-optimal BPDU is continuously sent to the root switch, the root switch will dispute the port, which is to prevent loops in the network. The remote switch cannot receive the BPDU of the root bridge because the line is single-pass, so it will elect itself as the root bridge and send BPDUs of itself as the root bridge at the same time.

[pmirel094]

Hello,

I have this problems with %STP-2-DISPUTE_DETECTED: Dispute detected on port port-channel when one of the 2 L2 10G link is in failure. I have a portchannel with 3 L2 links. 

Two of them is 10G L2 and one is L2 1G. One is active all the time and the last two are in stand-by. When the first one is going down do to a fiber-cut or something like that the second 10G L2 will go in status connected till the first 10G will be back. When this automatic swap of links it is made I handle this problem on all vlans %STP-2-DISPUTE_DETECTED: Dispute detected on port port-channel...

I have 4 Nexus two of them  in PROD Datacenter and the other two in Disaster recovery datacenter and they are connected with this 3 L2 Links.

Do you have an idea how can I not have this problem in the with vlan dispute. This couses disconecting of some applications.