VLAN STP showing BLK

[support1@lima.co.uk]

Hi all,

I have applied STP to interface 1/34/1 and attemping to use 1/33 as the default path for traffic, it is still showing BLK... any suggestions.

conf interface e1/34/1
spanning-tree vlan 104 cost 2500
spanning-tree vlan 107 cost 2500
spanning-tree vlan 109 cost 2500
spanning-tree vlan 110 cost 2500
spanning-tree vlan 129 cost 2500
spanning-tree vlan 132 cost 2500
spanning-tree vlan 150 cost 2500
spanning-tree vlan 151 cost 2500

interface Ethernet1/33
spanning-tree port type network
interface Ethernet1/34/1
spanning-tree port type network
spanning-tree vlan 104,107,109-110,129,132,150-151 cost 2500

VLAN0107
Spanning tree enabled protocol rstp
Root ID Priority 107
Address 0023.04ee.be0a
Cost 3500
Port 133 (Ethernet1/34/1)
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Bridge ID Priority 32875 (priority 32768 sys-id-ext 107)
Address 70ea.1a71.8fd3
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Interface Role Sts Cost Prio.Nbr Type
---------------- ---- --- --------- -------- --------------------------------
Po1 Desg FWD 250 128.4096 (vPC peer-link) Network P2p
Eth1/2 Desg FWD 500 128.5 P2p
Eth1/3 Desg FWD 500 128.9 P2p
Eth1/4 Desg FWD 500 128.13 P2p
Eth1/7 Desg FWD 500 128.25 P2p
Eth1/9 Desg FWD 500 128.33 P2p
Eth1/10 Desg FWD 500 128.37 P2p
Eth1/11 Desg FWD 500 128.41 P2p
Eth1/12 Desg FWD 500 128.45 P2p
Eth1/13 Desg FWD 500 128.49 P2p
Eth1/14 Desg FWD 500 128.53 P2p
Eth1/15 Desg FWD 500 128.57 P2p
Eth1/16 Desg FWD 500 128.61 P2p
Eth1/17 Desg FWD 500 128.65 P2p
Eth1/22 Desg FWD 500 128.85 P2p
Eth1/23 Desg FWD 500 128.89 P2p
Eth1/24 Desg FWD 500 128.93 P2p
Eth1/27 Desg FWD 500 128.105 P2p
Eth1/28 Desg FWD 500 128.109 P2p
Eth1/33 Altn BLK 2000 128.129 Network P2p
Eth1/34/1 Root FWD 2500 128.133 Network P2p

Should the above be showing at Root on 1/33 ??

[support1@lima.co.uk]

Seems the 1/34/1 is still the preffered path even though 1/33 has a lower stp cost..

Port 129 (Ethernet1/33) of VLAN0107 is alternate blocking
Port path cost 2000, Port priority 128, Port Identifier 128.129
Designated root has priority 107, address 0023.04ee.be0a
Designated bridge has priority 32875, address 8c60.4fca.b442
Designated port id is 128.288, designated path cost 2000
Timers: message age 17, forward delay 0, hold 0
Number of transitions to forwarding state: 0
The port type is network
Link type is point-to-point by default
BPDU: sent 21253081, received 21254713

Port 133 (Ethernet1/34/1) of VLAN0107 is root forwarding
Port path cost 2500, Port priority 128, Port Identifier 128.133
Designated root has priority 107, address 0023.04ee.be0a
Designated bridge has priority 32875, address 8c60.4fca.b142
Designated port id is 128.416, designated path cost 1000
Timers: message age 16, forward delay 0, hold 0
Number of transitions to forwarding state: 2
The port type is network
Link type is point-to-point by default
BPDU: sent 21253218, received 21257182

[support1@lima.co.uk]

Set the port priority to 32 

int 1/33

spanning tree vlan 107 port prirorty 32 - still showing blocking.

[MHM Cisco World]

This is vPC which by default and can not change it must make vPC peer link akways FWD. 

[balaji.bandi]

can you post show vpc and show vpc consistencey ?

Nexus vPC the config should be same on both the switches in the vPC

[support1@lima.co.uk]

Switch1
 show vpc
Legend:
(*) - local vPC is down, forwarding via vPC peer-link

vPC domain id : 20
Peer status : peer adjacency formed ok
vPC keep-alive status : peer is alive
Configuration consistency status : success
Per-vlan consistency status : success
Type-2 consistency status : failed
Type-2 inconsistency reason : SVI type-2 configuration incompatible
vPC role : primary
Number of vPCs configured : 3
Peer Gateway : Disabled
Dual-active excluded VLANs : -
Graceful Consistency Check : Enabled
Auto-recovery status : Disabled
Delay-restore status : Timer is off.(timeout = 30s)
Delay-restore SVI status : Timer is off.(timeout = 10s)
Operational Layer3 Peer-router : Disabled
Virtual-peerlink mode : Disabled

vPC Peer-link status
---------------------------------------------------------------------
id Port Status Active vlans
-- ---- ------ -------------------------------------------------
1 Po1 up 1,3,104,107,109-110,129,132,150-151,601-602,
610-617,621-623,633,640,699,1614,1650,1660-1665,
1680-1681,1695,1698-1699

vPC status
----------------------------------------------------------------------------
Id Port Status Consistency Reason Active vlans
-- ------------ ------ ----------- ------ ---------------
11 Po11 up success success 633

15 Po15 up success success 640

17 Po17 up success success 640

Please check "show vpc consistency-parameters vpc <vpc-num>" for the
consistency reason of down vpc and for type-2 consistency reasons for
any vpc.

# show vpc consistency-parameters vlans

Name Type Reason Code Pass Vlans
------------- ---- ---------------------- -----------------------
STP MST Simulate PVST 1 SUCCESS 0-4095
STP Port Type, Edge 1 SUCCESS 0-4095
BPDUFilter, Edge BPDUGuard
STP MST Region Name 1 SUCCESS 0-4095
STP Disabled 1 SUCCESS 0-4095
STP Mode 1 SUCCESS 0-4095
STP Bridge Assurance 1 SUCCESS 0-4095
STP Loopguard 1 SUCCESS 0-4095
Xconnect Vlans 1 SUCCESS 0-4095
STP MST Region Instance to 1 SUCCESS 0-4095
VLAN Mapping
STP MST Region Revision 1 SUCCESS 0-4095
Pass Vlans - 0-4095
#

Switch 2

# show vpc
Legend:
(*) - local vPC is down, forwarding via vPC peer-link

vPC domain id : 20
Peer status : peer adjacency formed ok
vPC keep-alive status : peer is alive
Configuration consistency status : success
Per-vlan consistency status : success
Type-2 consistency status : failed
Type-2 inconsistency reason : SVI type-2 configuration incompatible
vPC role : secondary
Number of vPCs configured : 3
Peer Gateway : Disabled
Dual-active excluded VLANs : -
Graceful Consistency Check : Enabled
Auto-recovery status : Disabled
Delay-restore status : Timer is off.(timeout = 30s)
Delay-restore SVI status : Timer is off.(timeout = 10s)
Operational Layer3 Peer-router : Disabled
Virtual-peerlink mode : Disabled

vPC Peer-link status
---------------------------------------------------------------------
id Port Status Active vlans
-- ---- ------ -------------------------------------------------
1 Po1 up 1,3,104,107,109-110,129,132,150-151,601-602,
610-617,621-623,633,640,699,1614,1650,1660-1665,
1680-1681,1695,1698-1699

vPC status
----------------------------------------------------------------------------
Id Port Status Consistency Reason Active vlans
-- ------------ ------ ----------- ------ ---------------
11 Po11 up success success 633

15 Po15 down* failed vpc port channel -
mis-config due to vpc
links in the 2
switches connected to
different partners
17 Po17 up success success 640

Please check "show vpc consistency-parameters vpc <vpc-num>" for the
consistency reason of down vpc and for type-2 consistency reasons for
any vpc.

# show vpc consistency-parameters
^
% Incomplete command at '^' marker.
interface Specify interface
vlans Vlans
vni Show vPC Consistency Parameters vni

# show vpc consistency ?
global Global Parameters
interface Specify interface
vlans Vlans
vni Show vPC Consistency Parameters vni
vpc Virtual Port Channel configuration

# show vpc consistency ?
global Global Parameters
interface Specify interface
vlans Vlans
vni Show vPC Consistency Parameters vni
vpc Virtual Port Channel configuration

# show vpc consistency vlans

Name Type Reason Code Pass Vlans
------------- ---- ---------------------- -----------------------
STP MST Simulate PVST 1 SUCCESS 0-4095
STP Port Type, Edge 1 SUCCESS 0-4095
BPDUFilter, Edge BPDUGuard
STP MST Region Name 1 SUCCESS 0-4095
STP Disabled 1 SUCCESS 0-4095
STP Mode 1 SUCCESS 0-4095
STP Bridge Assurance 1 SUCCESS 0-4095
STP Loopguard 1 SUCCESS 0-4095
Xconnect Vlans 1 SUCCESS 0-4095
STP MST Region Instance to 1 SUCCESS 0-4095
VLAN Mapping
STP MST Region Revision 1 SUCCESS 0-4095
Pass Vlans - 0-4095

[MHM Cisco World]

Cisco Nexus: Getting Error “vpc links in the 2 switches connected to different partners" - Cisco Community

[support1@lima.co.uk]

Thanks, are you sure this vpc issue would be causing this?

Global parametres appear ok, slight difference with a single vlan

show vpc consistency-parameters global

Legend:
Type 1 : vPC will be suspended in case of mismatch

Name Type Local Value Peer Value
------------- ---- ---------------------- -----------------------
STP MST Simulate PVST 1 Enabled Enabled
STP Port Type, Edge 1 Normal, Disabled, Normal, Disabled,
BPDUFilter, Edge BPDUGuard Disabled Disabled
STP MST Region Name 1 "" ""
STP Disabled 1 None None
STP Mode 1 Rapid-PVST Rapid-PVST
STP Bridge Assurance 1 Enabled Enabled
STP Loopguard 1 Disabled Disabled
STP MST Region Instance to 1
VLAN Mapping
STP MST Region Revision 1 0 0
Interface-vlan admin up 2 1614,1650,1660,1662, 1614,1650,1661,1663,
1664,1680,1695, 1665,1681,1695,
1698-1699 1698-1699
Interface-vlan routing 2 1,104,107,1614,1650, 1,1614,1650,1661,1663,
capability 1660,1662,1664,1680, 1665,1681,1695,
1695,1698-1699 1698-1699
Xconnect Vlans 1
QoS (Cos) 2 ([0-7], [], [], [], ([0-7], [], [], [],
[], [], [], []) [], [], [], [])
Network QoS (MTU) 2 (1500, 1500, 1500, (1500, 1500, 1500,
1500, 1500, 1500, 1500, 1500, 1500,
1500, 1500) 1500, 1500)
Network Qos (Pause: 2 (F, F, F, F, F, F, F, (F, F, F, F, F, F, F,
T->Enabled, F->Disabled) F) F)
Input Queuing (Bandwidth) 2 (0, 0, 0, 0, 0, 0, 0, (0, 0, 0, 0, 0, 0, 0,
0) 0)
Input Queuing (Absolute 2 (F, F, F, F, F, F, F, (F, F, F, F, F, F, F,
Priority: T->Enabled, F) F)
F->Disabled)
Output Queuing (Bandwidth 2 (100, 0, 0, 0, 0, 0, (100, 0, 0, 0, 0, 0,
Remaining) 0, 0) 0, 0)
Output Queuing (Absolute 2 (F, F, F, F, F, F, F, (F, F, F, F, F, F, F,
Priority: T->Enabled, T) T)
F->Disabled)
Allowed VLANs - 1,3,104,107,109-110, 1,3,104,107,109-110,
129,132,150-151, 129,132,150-151,
601-602,610-617, 601-602,610-617,
621-623,633,640,699, 621-623,633,640,699,
1614,1650,1660-1665, 1614,1650,1660-1665,
1680-1681,1695, 1680-1681,1695,
1698-1699 1698-1699
Local suspended VLANs - - -

[balaji.bandi]

First you need to fix the below :

Type-2 consistency status : failed
Type-2 inconsistency reason : SVI type-2 configuration incompatible

you can search many troubleshooting tips can be find with the errors - this may have cause of issue, but since we do not know your topology to asses correctly.

Also, Lower STP costs will be preferred always .

STP election process :

Spanning Tree Protocol (STP) – 
As IEEE STP is used to make a loop-free network by monitoring the network to track all the links and shut down the redundant ones. These are some important terms related to Spanning Tree Protocol: 

• Bridge Priority Data Unit (BPDU) – It contains the Bridge ID, Sender’s Bridge ID, Cost to the Root Bridge, Timer values on Root Bridge. All switches exchange BPDU in order to elect root bridge. The switch with the lowest Bridge ID become the root bridge.
• Bridge ID – It is an 8-byte field that is a combination of bridge priority (2 bytes) and Base Mac address (6 bytes) of a device. If there is a tie on bridge priority then the Base Mac address is considered.
• Bridge Priority – It is a priority, which is assigned to every switch, 32768 by default.
• Root Bridge – The root bridge is the bridge with the lowest Bridge ID. All the decisions like which ports are the root ports (the port with the best path to the root bridge) are made from the perspective of the root bridge.
• Path cost – A switch may encounter one or more switches in the path to the root bridge. All the paths are analyzed and the path with the lowest cost will be selected. 

yout

[support1@lima.co.uk]

show vpc consistency-parameters vpc 11

Legend:
Type 1 : vPC will be suspended in case of mismatch

Name Type Local Value Peer Value
------------- ---- ---------------------- -----------------------
delayed-lacp 1 disabled disabled
mode 1 active active
Switchport Isolated 1 0 0
Interface type 1 port-channel port-channel
LACP Mode 1 on on
Virtual-ethernet-bridge 1 Disabled Disabled
Speed 1 40 Gb/s 40 Gb/s
Duplex 1 full full
MTU 1 1500 1500
Port Mode 1 access access
Native Vlan 1 1 1
Admin port mode 1 access access
STP Port Guard 1 Default Default
STP Port Type 1 Edge Port Edge Port
STP MST Simulate PVST 1 Default Default
lag-id 1 [(0, 0-b7-71-7d-9f-dd, [(0, 0-b7-71-7d-9f-dd,
0, 0, 0), (7f9b, 0, 0, 0), (7f9b,
0-23-4-ee-be-14, 800b, 0-23-4-ee-be-14, 800b,
0, 0)] 0, 0)]
Allow-Multi-Tag 1 Disabled Disabled
Vlan xlt mapping 1 Disabled Disabled
vPC card type 1 N9K TOR N9K TOR
Allowed VLANs - 633 633
Local suspended VLANs - - -

show vpc consistency-parameters vpc 15

Legend:
Type 1 : vPC will be suspended in case of mismatch

Name Type Local Value Peer Value
------------- ---- ---------------------- -----------------------
delayed-lacp 1 disabled disabled
mode 1 active active
Switchport Isolated 1 0 0
Interface type 1 port-channel port-channel
LACP Mode 1 on on
Virtual-ethernet-bridge 1 Disabled Disabled
Speed 1 40 Gb/s 40 Gb/s
Duplex 1 full full
MTU 1 1500 1500
Port Mode 1 access access
Native Vlan 1 1 1
Admin port mode 1 access access
STP Port Guard 1 Default Default
STP Port Type 1 Edge Port Edge Port
STP MST Simulate PVST 1 Default Default
lag-id 1 [(0, [(0,
b8-59-9f-9c-43-21, 0, b8-59-9f-9c-43-20, 0,
0, 0), (7f9b, 0, 0), (7f9b,
0-23-4-ee-be-14, 800f, 0-23-4-ee-be-14, 800f,
0, 0)] 0, 0)]
Allow-Multi-Tag 1 Disabled Disabled
Vlan xlt mapping 1 Disabled Disabled
vPC card type 1 N9K TOR N9K TOR
Allowed VLANs - 640 640
Local suspended VLANs - - -

show vpc consistency-parameters vpc 17

Legend:
Type 1 : vPC will be suspended in case of mismatch

Name Type Local Value Peer Value
------------- ---- ---------------------- -----------------------
delayed-lacp 1 disabled disabled
mode 1 active active
Switchport Isolated 1 0 0
Interface type 1 port-channel port-channel
LACP Mode 1 on on
Virtual-ethernet-bridge 1 Disabled Disabled
Speed 1 40 Gb/s 40 Gb/s
Duplex 1 full full
MTU 1 1500 1500
Port Mode 1 access access
Native Vlan 1 1 1
Admin port mode 1 access access
STP Port Guard 1 Default Default
STP Port Type 1 Edge Port Edge Port
STP MST Simulate PVST 1 Default Default
lag-id 1 [(0, b8-59-9f-c3-2-4b, [(0, b8-59-9f-c3-2-4b,
0, 0, 0), (7f9b, 0, 0, 0), (7f9b,
0-23-4-ee-be-14, 8011, 0-23-4-ee-be-14, 8011,
0, 0)] 0, 0)]
Allow-Multi-Tag 1 Disabled Disabled
Vlan xlt mapping 1 Disabled Disabled
vPC card type 1 N9K TOR N9K TOR
Allowed VLANs - 640 640
Local suspended VLANs - - -

[MHM Cisco World]

my previous answer for this failed 

15 Po15 down* failed vpc port channel -
mis-config due to vpc
links in the 2
switches connected to
different partners

[MHM Cisco World]

I need to see the topology (please write the PO number you use in topology to understand what happened here) 

[Georg Pauwen]

Hello,

I have not followed the entire thread, but what if you configure root guard on port 34 (which effectively makes sure that port cannot be the root port) ?

[support1@lima.co.uk]

That port is required to be root for a number of vlans..

[paul driver]

Hello
The designated path cost for eth1/34/1 does show a lower value than eth1/33 for their respective lan segments, which is the total cost calculated by STP for those ports to get back to the root, which suggest eth1/34 upstream connection is shorter to the root, 

Port 129 (Ethernet1/33) of VLAN0107 is alternate blocking
Port path cost 2000, Port priority 128, Port Identifier 128.129
Designated root has priority 107, address 0023.04ee.be0a
Designated bridge has priority 32875, address 8c60.4fca.b442
Designated port id is 128.288, designated path cost 2000

Port 133 (Ethernet1/34/1) of VLAN0107 is root forwarding
Port path cost 2500, Port priority 128, Port Identifier 128.133
Designated root has priority 107, address 0023.04ee.be0a
Designated bridge has priority 32875, address 8c60.4fca.b142
Designated port id is 128.416, designated path cost 1000

However --- The interface received path cost should take preference between those two ports, but this output seems suggest the upstream switch via eth1/33 has a physical issue, so at present it wont matter how high this switches eth1/34/1 stp port cost is its the only valid path back to root for it..