Nexus 31108PC-V and Nexus 31108TC-V dual sided VPC issue

[Caranrack]

Hi!

I would like to ask for help due to issue that I am currently experiencing while configuring our pairs of Nexus 31108PC-V and Nexus 31108TC-V in dual sided VPC.

Afer configuring basic prerequisites for VPC function, one of my switches in second pair got left out of VPC. I tried everything, but cannot get port-channel on that switch to be part of VPC.

Only clue that I get in logs are following messages:

2022 May 16 18:15:36 N3K-DC-1 %ETHPORT-5-IF_DUPLEX: Interface port-channel3, ope
rational duplex mode changed to Full
2022 May 16 18:15:36 N3K-DC-1 %ETHPORT-5-IF_RX_FLOW_CONTROL: Interface port-chan
nel3, operational Receive Flow Control state changed to off
2022 May 16 18:15:36 N3K-DC-1 %ETHPORT-5-IF_TX_FLOW_CONTROL: Interface port-chan
nel3, operational Transmit Flow Control state changed to off

VPC status on all my switches is the following:

N3K-AGG-1# sh vpc
Legend:
(*) - local vPC is down, forwarding via vPC peer-link

vPC domain id : 1
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 : success
vPC role : primary
Number of vPCs configured : 1
Peer Gateway : Enabled
Dual-active excluded VLANs : -
Graceful Consistency Check : Enabled
Auto-recovery status : Enabled, timer is off.(timeout = 240s)
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 Po2 up 1,5,13,43,60,88,90,100-110,120-123,140,150,

169-172,192,200-209,219-220

vPC status
----------------------------------------------------------------------------
Id Port Status Consistency Reason Active vlans
-- ------------ ------ ----------- ------ ---------------
3 Po3 up success success 1,5,13,43,60,88,90

,100-110,120-123,

140,150,169-172,

192,200-209,

219-220

N3K-AGG-2# sh vpc
Legend:
(*) - local vPC is down, forwarding via vPC peer-link

vPC domain id : 1
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 : success
vPC role : secondary
Number of vPCs configured : 1
Peer Gateway : Enabled
Dual-active excluded VLANs : -
Graceful Consistency Check : Enabled
Auto-recovery status : Enabled, timer is off.(timeout = 240s)
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 Po2 up 1,5,13,43,60,88,90,100-110,120-123,140,150,

169-172,192,200-209,219-220

vPC status
----------------------------------------------------------------------------
Id Port Status Consistency Reason Active vlans
-- ------------ ------ ----------- ------ ---------------
3 Po3 up success success 1,5,13,43,60,88,90

,100-110,120-123,

140,150,169-172,

192,200-209,

219-220

N3K-DC-1# sh vpc
Legend:
(*) - local vPC is down, forwarding via vPC peer-link

vPC domain id : 2
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 : success
vPC role : secondary
Number of vPCs configured : 1
Peer Gateway : Enabled
Dual-active excluded VLANs : -
Graceful Consistency Check : Enabled
Auto-recovery status : Enabled, timer is off.(timeout = 240s)
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 Po2 up 1,5,13,43,60,88,90,100-110,120-123,140,150,

169-172,192,200-209,219-220

vPC status
----------------------------------------------------------------------------
Id Port Status Consistency Reason Active vlans
-- ------------ ------ ----------- ------ ---------------
3 Po3 down* success success -

N3K-DC-2# sh vpc
Legend:
(*) - local vPC is down, forwarding via vPC peer-link

vPC domain id : 2
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 : success
vPC role : primary
Number of vPCs configured : 1
Peer Gateway : Enabled
Dual-active excluded VLANs : -
Graceful Consistency Check : Enabled
Auto-recovery status : Enabled, timer is off.(timeout = 240s)
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 Po2 up 1,5,13,43,60,88,90,100-110,120-123,140,150,

169-172,192,200-209,219-220

vPC status
----------------------------------------------------------------------------
Id Port Status Consistency Reason Active vlans
-- ------------ ------ ----------- ------ ---------------
3 Po3 up success success 1,5,13,43,60,88,90

,100-110,120-123,

140,150,169-172,

192,200-209,

219-220

I have attached my configuration and I do hope that someone is willing to take a look and enlighten me what did I do wrong.

[MHM Cisco World]

Your Config is perfect no problem 
can you check show spanning tree 
check the PO is BLK status or bridge Assurance is BLK the PO. 

if that case can you config PO interconnect pairs with type normal spanning tree port.

[Caranrack]

Thank you for your answer. Seems that we are onto somthing since I too had that same idea.

All VLANs on PO on DC1 switch to other switch pair are blocked. 

However, I am unable to bring them up no matter the STP configuration change. 

[MHM Cisco World]

OK
shut down the PO vPC in all Nexus 
make the 
operational primary in Lower Pair for example AGG-1 above it Upper pair directly is operational primary DC-1
config the Upper pair Operational Primary DC-1 be primary root.
config the Upper pair Operational Secondary DC-2 be secondary root.

no shut the PO vPC in all Nexus 

[Caranrack]

I did as you instructed. Result is still the same.

[Caranrack]

I even tried to disable STP globally on all switches, but with no result.

[MHM Cisco World]

Do you config primary and secondary and root primary as i mention.

The upper two pair dc-1 and dc-2 must be root for double sided.

[Caranrack]

Yes, that is exacatly what I did.

Domain 1 primary-AGG1

Domain 2 primary-DC1

STP root primary for all VLANs-DC1

STP root secondary for all VLANs-DC2

And result is that DC1 still has PO down. I even rebooted all switches and it is always the same.

[paul driver]

Hello

Dc1 switch

• delete PO3
• default it’s related physical interfaces and shutdown 
• re-append channel-group on both physical interface and let PC automatically be created 
• append vlan pruning to the new PC this should propagate down to its related physical interfaces  
• enable PC

[Caranrack]

Thank you for your answer.

I did everything in your instructions but result is the same.

[Caranrack · Accepted solution]

I need to apologize to everyone that wasted their time to help me. It turned out to be layer 1 issue. Friend jumped in to help me and we discovered that one cable was not able to provide set 10G speed that was static set so whole PO went down due to that. 

Everything is working now. I will mark this as solution so everyone who is looking for an answer to same problem is aware of this issue.

[MHM Cisco World]

Thanks A Lot.

[Caranrack]

Thank you for your time. 

[MHM Cisco World]

You are so welcome friend.