One N5K down than Traffic was not flowing via 2nd N5K

[Dipesh Patel]

Dear Experts,

When switch – A goes down than Servers were not reachable.

　

Topology :

CORE Ten5/1 --- to N5K- Switch A on eth1/25

CORE Ten6/1 --- to N5K- Switch B on Eth 1/25

CORE Ten5/1 and ten 6/1 both bundled in Po20

On N5K Switch A and B --- Port Po20 configured with vPC 20

N5K Switch A to N5K switch B both connected via vPC Peer link (Eth 1/31 to Eht1/31)

　

Switch - A

VLAN0061

Spanning tree enabled protocol rstp

Root ID Priority 4157

Address 001d.a22e.0b80

Cost 4

Port 4115 (port-channel20)

Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Bridge ID Priority 32829 (priority 32768 sys-id-ext 61)

Address 547f.ee1b.b781

Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Interface Role Sts Cost Prio.Nbr Type

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

Po20 Root FWD 1 128.4115 (vPC) P2p Peer(STP)

Po55 Desg FWD 1 128.4150 (vPC peer-link) Network P2p

Po71 Desg FWD 1 128.4166 (vPC) Edge P2p

Po72 Desg FWD 1 128.4167 (vPC) Edge P2p

Po501 Desg FWD 1 128.4596 P2p

Po502 Desg FWD 1 128.4597 P2p

　

Switch - B

VLAN0061

Spanning tree enabled protocol rstp

Root ID Priority 4157

Address 001d.a22e.0b80

Cost 5

Port 4150 (port-channel55)

Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Bridge ID Priority 32829 (priority 32768 sys-id-ext 61)

Address 547f.ee1d.173c

Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Interface Role Sts Cost Prio.Nbr Type

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

Po20 Root FWD 1 128.4115 (vPC) P2p

Po55 Root FWD 1 128.4150 (vPC peer-link) Network P2p

Po71 Desg FWD 1 128.4166 (vPC) Edge P2p

Po72 Desg FWD 1 128.4167 (vPC) Edge P2p

Po401 Desg FWD 1 128.4496 P2p

Po402 Desg FWD 1 128.4497 P2p

For Spanning-tree parameter i have check I found something unexpected.

Please help to resolve this issue.

Regards        

[Andras Dosztal]

Does "show vpc consistency- parameters" show any errors? Do you mean powering off by going down, or just losing the uplink?


Sent from Cisco Technical Support Android App

[Dipesh Patel]

No error. All vpC are working ok.

One Switch is not working due to Temparature Policy triggereed.

Pls suggest. Why two root are there on one switch ?

Regards

[Vishwa Mishra]

Hi Dipesh ,

That is not a issue at all ,peer-link port should always be in forwarding so its expected to see 2 root ports on one of the peers , one for the peer-link and other towards your root bridge.

Port on the operational primary should be desg port and operational seconday should be root port ideally.

Regards

Vishwa