Network OS Administration Guide

Supporting Network OS 6.0.1a

Part Number: 53-1003768-04

Virtual IP address configuration scenarios

Virtual IP address may be assigned to a switch whenever it is the principal switch in the cluster. The configuration scenarios that may occur are described below.

Table 17 Virtual IP address configuration scenarios

Scenario

Description

First time cluster formation

When the cluster is first being formed, and if the virtual IP address is already configured, the principal switch is assigned the Virtual IP address. If no Virtual IP configuration exists, then the principal switch can be access using the management port IP address.

Virtual IP configuration

When you configure the virtual IP address for a cluster the first time, the address is bound to the management interface of the principal switch.

Principal switch failover

If the principal switch becomes a secondary switch while the virtual IP address is assigned to its management interface, then the virtual IP address is reassigned to the new principal switch.

Principal switch goes down

When the principal switch in the cluster goes down, the virtual IP address is released from its management interface. The virtual IP address will be assigned to the next switch that becomes the principal switch.

Principal switch chassis is disabled

When the chassis disable command is executed on the principal switch, the virtual IP address is released from its management interface. The virtual IP address will be assigned to the next switch that becomes the principal switch.

Virtual IP removal

If you remove the virtual IP address from the configuration, then the address is unbound from management interface of the principal switch. In this case, the principal switch can still be accessed by using the management port’s IP address.

Trivial merge

In the event that two clusters merge together, the global configuration of the smaller cluster (Cluster A) is overwritten by the larger cluster (Cluster B). During this time, the virtual IP address is unbound from the principal switch of Cluster A. The virtual IP address of Cluster B can now be used to access the principal of new merged cluster. If the virtual IP address of Cluster B is not configured, there will not be a virtual IP address in the merged cluster.

Cluster reboot

When the cluster reboots, the virtual IP address is persistent and is bound to the new principal switch.

Cluster Islanding

If the ISL link goes down between two or more clusters that are forming, the principal switch in the original cluster retains the virtual IP address. The new principal switch in the second cluster will perform a check to confirm that the virtual IP address is not in use. If it is in use, then the address is not assigned to the switch and an error is logged in RASLog.

Virtual MAC address

Virtual MAC address are not supported by virtual IP addresses.

Management port primary IPv4 address

For a virtual IP address to work correctly, the management port’s IPv4 address should be assigned and functional.