Adding 3rd C9500 Switch in existing stackwise C9500 Switches

[csm_awais]

Hi,

I am running a scenario in which I am using 2 Cisco C9500 switches as stackwise virtual link.(2 40 gig ports, and 1 port is used dual active  detection are used), can I add 3rd switch in stackwise virtual or not?

Thanks,

[Kasun Bandara]

@csm_awais as per below guides, this supports only 2 switches. virtual links can go up to 8.

https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst9500/software/release/17-9/configuration_guide/ha/b_179_ha_9500_cg/configuring_cisco_stackwise_virtual.html

https://www.cisco.com/c/en/us/products/collateral/switches/catalyst-9000/nb-06-cat-9k-stack-wp-cte-en.html#Catalyst9400and9500

https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst9500/software/release/16-6/configuration_guide/b_166_ha_9500/b_166_ha_9500_chapter_01.html#concept_gbh_lxx_31b

[marce1000]

 FYI : https://community.cisco.com/t5/switching/stackwise-virtual-on-3-x-c9500-40x/m-p/4114349/highlight/true#M489372

M.

[csm_awais]

Thanks for the link, it is really helpful.

[Joseph W. Doherty]

No.

[Leo Laohoo]

If 2 x 48-port 9500 is not enough then a re-design of the core network may be required.  

Because the 9500 will never allow the existence of the 9300X-48Y, buying 9300X-24Y would be a very expensive option.  The best would then be a 9600 (still cheaper than a 9400).  

Save up to 16% on Catalyst 9600X next-generation line cards and supervisor

[csm_awais]

Hi Leo Thanks,

I have 2 C9500 Switches with 24 10G and 4 40G connected in stackwise virtual. Port 25 and 26 on both switches is used for stackwise virtual and port 27 is used for Dual Active Detection. My client want to add 3rd switches of the same specification as a existing stack. Below is the design.

[Leo Laohoo]

Then replace the entire lot with 2 x 48-port 9500.  

If 92 ports is not enough, consider a 9400 or a 9600.

[balaji.bandi]

SVL Limit to only 2 Devices, you can not add another member in to the exiting SVL, you can add new Cat 9500 in different way to use it but it can not be in the virtual domain.

Tell the client to bring another 2 9500 can be another SVL domain to and join to exiting domain 

or replace with chassis as suggested.

If only one switch, install in Layer 2 connection with dual uplink connection to exiting cat 9500