3750 Stackwise and Master Election

[Marc.Halleux]

Hi,

We have a stack composed by 2 x 3750G-12S-E and 2x 3750-48TS-S. I want to be sure that the 2x 3750-48TS-S will never be elected as Master.

Regards,

Marc.

[Prashanth Krishnappa]

Make the stack priority 1

http://www.cisco.com/univercd/cc/td/doc/product/lan/cat3750/12119ea1/3750scg/swstack.htm#1153255

W2S-3.3-C3750G-24T-B(config)#switch ?

<1-9> Switch Number

W2S-3.3-C3750G-24T-B(config)#switch 8 priority ?

<1-15> Switch Priority

W2S-3.3-C3750G-24T-B(config)#switch 8 priority

[Marc.Halleux]

Thank you for your response.

But, this command just mean that the switch with priority of 1 will be not elected as master if other switch with higher priority exist in the stack. This could cause problems if, for example, we reboot the Master. The switch with priority of one was elected as master. And because this switch is an "SMI" version, we lost the "EMI" functionnality.

So my question is, is it possible to force it to never become the Master? We prefer to lost for a short time (the reboot time) the connection, than to lost the "EMI" functionnality.

Regards,

Marc.

[rmiles]

But wouldn't the EMI switch cause a stack re-election if the power was cycled? In this case you would only have the SMI as master during the reboot of the EMI switch. You say that you would rather lose connectivity all together rather than lose EMI functionality. I don't understand why though? In either case you have lost your layer 3 functions right?

[DWAM_2]

Hello,

You will find stack master election process here

and recommandations about smi - emi cohabitation stack.

http://www.cisco.com/en/US/products/hw/switches/ps5023/products_configuration_guide_chapter09186a00801a6558.html#1044402

The system-level features supported on the stack master are supported on the entire switch stack. If the switch stack must have switches running both standard multilayer image (SMI) and enhanced multilayer image (EMI) software, we recommend that a switch running the EMI software be the stack master. EMI features are unavailable if the stack master is running the SMI software.

Regards.