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Should standby VC module become active after the (active) upstream switch ports are disabled?

 
chuckk281
Trusted Contributor

Should standby VC module become active after the (active) upstream switch ports are disabled?

Stephen was helping his customer test for a failover condition:

 

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Customer has 2 x Virtual Connect Flex-Fabric (VC/FF) modules with a single Shared Uplink set using ports X4 and X5 on both modules. One VC/FF module is connected to one upstream Cisco switch and the other VC/FF to another Cisco switch. The SUS has 5 x VLAN networks associated with it, all of which have the SmartUplink feature enabled.

 

Customer is testing resilience to upstream switch failure by disabling the ports on the upstream Cisco switch attached to the active VC/FF module.

 

BEFORE the upstream ports are turned off, everything is working fine and the VC ports are shown as:-

 

Module1 X4 Linked-Active

Module1 X5 Linked-ACtive

Module2 X4 Linked-Standby

Module2 X5 Linked-Standby

 

AFTER the Cisco ports have been turned off the status of the four VC ports shows up as:-

 

Module1 X4 Not-Linked

Module1 X5 Not-Linked

Module2 X4 Linked-Standby

Module2 X5 Linked-Standby

 

i.e. The previously Standby module2 has NOT become active.

 

Is this expected behaviour? Myself and the customer expected to see the VC/FF module2 become Active and communication with the blades to continue, so we expected to see:-

 

Module1 X4 Not-Linked

Module1 X5 Not-Linked

Module2 X4 Linked-Active

Module2 X5 Linked-Active

 

What do we need to do to make the system resilience to an upstream switch failure?

 

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Info from Dave:

 

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Per your comment " single Shared Uplink set" would indicate an Active/Standby configuration.

We only enable 'SmartLink' for the Active/Active setups. That may be causing your issue.

SmartLink disables that module's downlinks when it loses all of a SUS uplinks.

 

A/S(without SmartLink) will move to the module with the best bandwidth.

i.e. Lose one or two uplinks on the Active module will switch over to the next Standby for that SUS module.

 

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Other comments or suggestions? Look at the configurations in the Virtual Connect Ethernet CookBook