3850 Redundancy

[sallyonsy]

Dear ,

 Kindly I am designing a network with core layer as below:

three switches 3850 stacking in one group:

WS-C850-24XS-S + WS-C3850-24XS-S + WS-C3850-24T-S

All three switches in one stack , all has the release 16.6 & IP base license.

I will have two stack groups for redundancy (each stack group contain three switches as above)

I want to check how can I configure these two sets of stack groups in the core layer ? Can I do it with HSRP or there is another way?

Thanks

Sally

[jcockburn]

Hi Sally,
HSRP and STP tweaking will work.

My question is how much redundancy do you want. If you think about it having 3850's in a stack is already creating a redundant system if you populate your connections correctly.
If you need the 'core' to be distributed across different physical cabinets then you need 2 stacks with HSRP or you could opt to use the stackwise virtual option which is also available
https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst3850/software/release/16-6/configuration_guide/b_166_stck_mgr_ha_3850/b_166_stck_mgr_ha_3850_chapter_010.pdf

My opinion is to use what is simple and what you and your techies understand...
Hope this helps you decide...
Ciao
JC

[sallyonsy]

Thanks for your reply.

I will have a group of edge switches , each connected through two uplink ports 10G LR ports to the core layer.

In the core layer I will terminate uplink port 1 from the access switch to stack group 1 & the second uplink from the access switch to the second stack group. 

My point was related that how can I make the two stacks group communicate with each other.

Can I use HSRP or stackwise virtual?

What is better in the design?

Thanks

Sally

[jcockburn]

Hi Sally,

As far as I know the stackwise virtual option does not work between already stacked switches. I might be wrong...

So that would leave you with only the one option using two stacks of 3 each switches, configured as collapsed core/distribution.

If your requirement is to have VLANs span across different access (edge) switches then you will need to have the HSRP with STP tweaking option. What I mean by tweaking is that you will need to pair the active HSRP side with the STP root Bridge for optimization of traffic flow.

If the requirement is to have unique VLANs per access(edge) switch then you may have Layer 3 links between access and core (thus no need for STP and HSRP), but for me it sounds like this is not the option.

I hope this helps.

Good luck and enjoy the experience

Ciao

JC