Mixed Stack 9300 and 9300X is it possible?

[ifabrizio]

Dear All,

I am reading the Cisco documentation about the switch models 9300 and 9300X.

I am panning to change the Distribution/Access (Collapsed Distribution/Access) that now is composed by oldest 4500.

The ideal configuration made with 9300 and 9300X in mixed stack is:

Qty	Model	Description
1	C9300X-48HX-A	Catalyst 9300 48-port 10G/mGig copper with modular uplink, UPOE+, Network Advantage
3	C9300-48T-A	Catalyst 9300 48-port 1G copper with modular uplinks, data only, Network Advantage
1	C9300X-24Y-A	Catalyst 9300 24-port 25G/10G/1G SFP28 with modular uplinks, Network Advantage
2	C9300X-NM-2C	Catalyst 9300 2 x 100G/40G dual rate QSFP Network Module
1	1100AC	AC Power Supply
3	350AC	AC Power Supply
1	715AC	AC Power Supply

In the Cisco documentation I found something that I don't understand, apparently it seems like a contradiction. First it is specified that the 9300 switches can be stacked with the 9300X, then the opposite is stated!? Can someone explain to me what this means?

Thanks in advance,

JF

[M02@rt37 · Accepted solution]

Hello @ifabrizio 

Best Practice: Only homogenous stacking is supported, that is, a stack of Cisco Catalyst 9300 Series Switches stack with only Cisco Catalyst 9300 Series Switches as stack members. Cisco Catalyst 9300L Series Switches stack with only Cisco Catalyst 9300L Series Switches as stack members. C9300-24UB, C9300-24UXB, and C9300-48UB switches can only be stacked with each other. Also, you cannot have a switch stack containing a mix of different license levels and can’t stack fixed uplinks with modular, but you can stack normal 9300 with 9300X at stack wise 480 level. 

To go further, when a stack group consists of a mix of Catalyst 9300 and Catalyst 9300X switches in a full ring topology, the stack will operate at the lower stack bandwidth supported by the Catalyst 9300 switches. Since the Catalyst 9300 supports a maximum stack throughput of 480 Gbps with StackWise-480, the entire mixed stack will be limited to that bandwidth, even though the Catalyst 9300X switches are capable of higher stack bandwidths (e.g., 1.6 Tbps).

During the initial stack formation, all the members will reload to establish the stack, and the mixed stack will function at the 480 Gbps throughput. This limitation is due to the fact that the stacking technology will default to the lowest common denominator to maintain compatibility among all stack members. Hence, while it is possible to mix the 9300 and 9300X switches in a stack, the advanced capabilities of the 9300X (like higher stack bandwidth) won't be fully utilized in this configuration.

[marce1000]

 - Albeit being none-authoritative ; check this out : https://www.lookingpoint.com/blog/adding-cisco-9300-with-cisco-9300x-stack

 M.

[Leo Laohoo]

9300X can be stacked with plain 9300 but the stacking speed will take a substantial performance hit. 

[Leo Laohoo]

If the 9300X-24Y is going to act as a core/distro, I'd made sure it is a completely separate unit logically due to stability purposes.  

Make it a habit of regularly rebooting the switches every 12 to 18 months.  Cold-reboot is better than the "reload" command.  And this is how it's done: 

1. Pull the power cables; 
2. Due to residual electrical power, pull the power supplies out
3. Wait until the fans of the PS stop spinning
4. Wait 10 seconds
5. Put the power supplies back in
6. Apply power.