Cisco 3750x BRP Priority

[Corneliu Paunescu]

I have 2 3750s connected via flexstack. Its working good no issues.

I have 8 2960s (each in stack of 4).

Each stack of 2960s, is connected via a port-channel to my 3750. But, I have a backup port-channel to my second 3750, just in case my first 3750 goes down.

I dont want to have both connections up, I just want it so that in case one of the connections goes down, the secondary one takes over.

Isnt that done thru spanning-tree cost?

This is my setup:

3750

The primary Connection:

interface Port-channel2
description Uplink to ETHSW05
snmp trap mac-notification change added
snmp trap mac-notification change removed
spanning-tree guard loop
spanning-tree cost 15

The backup port-channel

interface Port-channel4

description BRP to ETHSW05

snmp trap mac-notification change added

snmp trap mac-notification change removed

spanning-tree guard loop

spanning-tree cost 1

Is my setup correct? Cause at the moment, both port-channels shows as up. Basically, I just want 2 2GB connections to each stack, one of them being a backup in case the first fails.

Thanks for the help...

[Reza Sharifi]

In a case when you have 2 portchannels to the same switch, the second portchannel will be in blocking mode, but the interfaces are still in up and up mode.  So, STP blocks one of them.

HTH

[Corneliu Paunescu]

Thank you.

So my configuration is correct?

Thanks...

[Jon Marshall]

Pick a vlan that is allowed on both both port channel interfaces and then do -

sh spanning-tree vlan

and you should see it being blocked on one of the switches. You should do this on he 2960s.

Jon

[Jon Marshall]

Hi Reza

Forgot to reply when i saw you in another post. Hope all is well with you

Jon

[Reza Sharifi]

Hi Jon,

All is well, thanks.

Good to see you are back after a long pause.

Have you recovered completely from your bike injury?

Reza

[Jon Marshall]

Reza

Have you recovered completely from your bike injury?

Pretty much yes although i do still get the odd twinge every now and then.

Glad to see your'e still active and i am learning more about VSS every time i read one of your posts.

Jon