CISCO SWITCH STACKING

[fmugambi]

Hello Team,

In need of help for cisco 3850 switch stacking concepts.

If have been running a single 3850 switch for sometime now, then bring in a new 3850 and stack it, are the configs synced automatically or there are configurations neeeded to be done?

What are the requirements for this setup?

Thank you.

[Kasun Bandara]

@fmugambi you can connect new switch to existing switch using stack cables. it will be a new stack member and in configuration you can see new set of interfaces added. use #sh run or #sh int status, to check the interfaces. configurations will expand automatically.. make sure both switches have same OS version and use correct stack cabling method to connect.

https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst3850/hardware/installation/guide/b_c3850_hig/b_c3850_hig_chapter_010.html

[Richard Pidcock]

The guide provided by @Kasun Bandara should give you all the information you need.   As recommended, be sure to run the same version on both switches.  When powering on, unless you have specifically configured a "Stack master priority", power on your original switch first the wait two minutes before powering on the second switch.  This will ensure your original switch becomes master.

[fmugambi]

question, does the second switch need to have physical connectivity to the rest of network infrastructure, to continue forwarding traffic without interruptions in a case where primary goes off?

[Richard Pidcock]

Yes, in the event your primary or (Master) switch fails, if there is not a network uplink to the rest of the network your entire stack would be down at that point.  I would recommend in your design that you consider uplinking from an interface on each of your switches.  Alternatively you would just have to accept the risk of that possible failure scenario.