VSS linking to 2 stacks

XEmmeX · ‎05-24-2016

Hi all,

I need some hints. I have to connect one VSS with 2 stacks in this way:

- VSS connected to stack 1 with fiber 1

- VSS connected to stack 2 with fiber 2

- stack 1 connected to stack 2 with fiber 3

Problem is that I need a sort of fault tolerance that should work in this way:

- fiber 1 is the only active link

- fiber 2 is in a sort of standby mode

- so stack 2 can reach VSS by fiber 3

I think that I could let the VSS manage this link by spanning-tree but I really don't know how I should set the fiber ports.

Any idea?

Furose M · ‎05-24-2016

Make stack#1 as STP Root bridge. the link between Stack#2 and VSS will be automatically blocked.

if you dont want STP to manage this, you can think of flex links.

http://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst6500/ios/12-2SX/configuration/guide/book/flexlink.html#wp1039328

http://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst6500/ios/12-2SX/configuration/guide/book/vss.html#wp1063892

why making it complex.. just go with STP :)

XEmmeX · ‎05-24-2016

Hi Furose,

thank you for the answer! I think I'll manage by STP as you told me. Should I configure only the fiber 1 and fiber 2 ports or do I need to configure the fiber 3 ports too?

(I've never used STP before, except for standard configuration :-( )

Furose M · ‎05-24-2016

you dont need to configure anything explicitly except "spanning root primary" in stack#1, if you wish to make it as Root bridge.

you can configure all the 3 links as normal trunk link or access link (depending on your design).

i would generally recommend using VSS as the STP root if it is the core of the network, but, to achieve your goal, this is the option.

XEmmeX · ‎05-24-2016

indeed the VSS is the core of the network and it's connected to other stacks too.

regarding the 3 links, they all will be configured as trunk.

I'll take a look, thank you

Furose M · ‎05-24-2016

if there are other stacks, then i would recommend leaving it as STP root and think about flex link option :)

paul driver · ‎05-24-2016

Hello

To clarify can you post a topology

res

Paul

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XEmmeX · ‎05-31-2016

Hi,

that's what I want to do

http://i.imgur.com/9PmOfJm.jpg

I wanna use one fiber link vs VSS at time. Just for claryfing, stack 1 and stack 2 use fiber 2 only when fiber 1 goes down.