Cluster has preemption enabled for Cisco

Vendor

Cisco

Description

Preemption is generally a bad idea in clustering, although sometimes it is the default setting. Indeni will alert if it's on.

Remediation Steps

It is generally best to have preemption disabled. Instead, once this device returns from a crash, you can conduct the failover manually.

FHRP preemption and delays features are not required. The vPC will forward traffic as soon as the links become available. Once a device recovers from a crash or reboot, you can conduct the failover manually.

Cisco recommends:

1. Configuring the FHRP with the default settings and without preempt when using vPC.

2. Make the vPC primary switch the FHRP active switch. This is not intended to improve performance or stability. It does make one switch responsible for the control plane traffic. This is a little easier on the administrator while troubleshooting.

How does this work?

This script logs into the Cisco Nexus switch using SSH and retrieves the HSRP state using the "show hsrp" command. The output includes a complete report of the HSRP state across all configure interfaces.

Why is this important?

This script logs into the Cisco Nexus switch using SSH and retrieves the HSRP state using the "show hsrp" command. The output includes a complete report of the HSRP state across all configure interfaces.

Without Indeni how would you find this?

It is possible to poll this data through SNMP. Preemption events would generate a syslog event.


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