What is split-brain scenario in vPC?

What is split-brain scenario in vPC?

Basically, in the vPC world, all links are set to forward, and nothing blocks at layer-2 because Spanning Tree is not really in place here. Cisco calls it a “split-brain” scenario. If that vPC peer-link fails for any reason, both switches assume the role of primary. This then creates the forwarding-loop-from-hell.

What is dual vPC?

Double-sided vPC: In double-sided vPC both the Nexus 7000 and Nexus 5000 switches run vPC. Each vPC pair of Nexus 5000 switches is connected to the aggregation vPC pair using a unique vPC.

What happens if vPC keepalive fails?

When the vPC peer link is lost, the operational secondary switch suspends all of its vPC member ports while the vPC member ports remain on the operational primary switch. If both switches reload, and only one switch boots up, auto-recovery allows that switch to assume the role of the primary switch.

What is the use of vPC in Nexus?

vPC (Virtual Port-Channel), also known as multichassis EtherChannel (MEC) is a feature on the Cisco Nexus switches that provides the ability to configure a Port-Channel across multiple switches (i.e. vPC peers). vPC is similar to Virtual Switch System (VSS) on the Catalyst 6500s.

How can we prevent split brain in vPC?

Best practice is to avoid the split brain scenario all together.

1. Configure the peer-link and the keep-alive from entirely independent resources.
2. Create a port-channel for the keep-alive.
3. Use a dedicated sub-interface for the keep-alive.

What is the difference between VSS and vPC?

3) VSS can support L3 port-channels across multiple chassis,however, vpc is used for L2 port-channels only. 4) VSS supports both PAgP and LACP,however, VPC only supports LACP. 5) VSS mainly used for campus environment whereas VPC is used for Data Center environment.

Can vPC be formed between 2 videos on the same device?

vPC Peer Links A single vPC domain between two VDCs on the same physical Cisco Nexus 7000 device is not supported.

How do you troubleshoot a vPC?

To verify vPCs using the CLI, perform one of these tasks:

1. Purpose. Command.
2. show running-config vpc. Checks the status of the vPCs.
3. show vpc peer-keepalive. Verifies that the vPC peers have the identical type-1 parameters.
4. show vpc consistency-parameters.
5. show tech-support vpc.
6. show port-channel summary.