0 Replies Latest reply: Nov 7, 2018 4:39 AM by Karim RSS

    Switch stacking best practice



      I am currently studding for ICND2 by reading the official cert guide and have a query relating to switch stacks.

      I understand the basics (and have quickly scanned over the section on StackWise in the official cert guide for CCNP SWITCH). Further trying to understand I have come across the Cisco campus lan best practices guide: https://www.cisco.com/c/en/us/products/collateral/switches/catalyst-6800-series-switches/guide-c07-733457.pdf that has lots of information.

      This is where my query lies. As I am not yet a network engineer yet I was hoping that people with experience could give me their view of best practices when designing a network that uses switch stacking.

      My understanding would be as follows for defining the stacks:

      1) Group access layer switches into stacks so that where possible VLANs are located in the same stacks. This is to reduce frame flooding impact.

      2) Access layer switch stacks located throughout building to ensure runs of less than 100m to clients.

      3) The first and last switch in the stack ring have two uplinks each to the distribution layer. These are bundled into two etherchannels, if distribution layer is standalone; and a single multi chassis etherchannel, if distribution layer uses VSS.

      4) Typically two distribution layer switches are used in each building (possibly interconnected by a VSL). One being the root of the spanning tree, the other in a standby role.

      While I appreciate each network would have differing requirements, would this be a fair overview of the process, or is it commonly done differently?

      As an after thought. Should the analysis decide that that only 1 or 2 access layer stacks are needed (e.g. at branch office). Would it still be normal practice to add a distribution layer switch? Or would the access switch stacks simply be connected together (and presumably a router onto one of them)? E.g. is there a magic number of access switches that it is then recommend to have a distribution layer?