Cisco 9400 StackWise Virtual with four Supervisor Module

[thomas.wiesner1]

Hi,

just a small question:

We want to buy two Cisco 9400 7 Slot Chassis and build up a StackWise Virtual.

Cisco recommends to put in one SUP-1XL supervisor module per Chassis.

If I am right, then when one modules fails, the whole chassis is down, right?

So I want to put in two supervisor modules per Chassis, but in the official guide theres a known limitation:

Cisco StackWise Virtual can be configured only on one supervisor module per chassis. You can install two supervisor modules in each chassis used in the Cisco StackWise Virtual solution. However, only one of the supervisor modules will be active; the other module will be powered off.

So what does "will be powered off" mean? Is it a cold-standby or is the module complete out of service?
Can we connect the second module(s) so when one of the modules goes down the whole chassis is still in service?

Thanks

Best regards

[Leo Laohoo]

---

@thomas.wiesner1 wrote:

If I am right, then when one modules fails, the whole chassis is down, right?

---

That's not how it works. 

When each chassis have two supervisor card and if one of the supervisor card fails, the chassis will still continue to chug along.

[thomas.wiesner1]

So, the "powered off" supervisor card kicks in and takes over?

Do you have any links where this situation is written down?

[Leo Laohoo]

---

@thomas.wiesner1 wrote:

So, the "powered off" supervisor card kicks in and takes over? 

Cisco 6500 VSS Redundancy System Overview

[thomas.wiesner1]

Thanks for this link, but it is for the 6500 series. Is it the same for the 9400 series? I cannot find anything related...

[Mark Malone]

hi
The concept is the same VSS/Stackwise does the same thing basically virual logical unit over physical switches, minimal failover time between supervisors between chassis , only 1 sup is required to run both chassis ,it acts as 1 logical unit , if one fails other supervisor immediatly takes over , its not powered off , its in an redundant state ready and waiting
what there saying above about powered off is if you had a quad sup setup 4 between both chassis which is not required and would leave one sup per chassis powered off while the stackwise is in place ,2 sups per chassis would just be required if standalone mode and not in stackwise so there is redundency in a single chassis if 1 sup fails

[Leo Laohoo]

---

@thomas.wiesner1 wrote:

Is it the same for the 9400 series? I cannot find anything related...

---

1.  9400 stackwise and VSS are no different.  You understand VSS, you'll understand stackwise. 

2.  Catalyst 9K was announced late 2018.  The documentations hasn't caught up yet.

[husain7989]

Hi,
I was dealing with the same situation, where I had 2*Cisco 9404R with Quad SUP, out of which only 2 were working. I got a confirmation from the Cisco engineering team that 17.3.1 will fix this limitation.

[RicardoMeza2021]

Hello, you had improvement when updating the IOS version or the same condition was maintained

Greetings.

[mrboogie081]

I wonder if you or anyone else, maybe someone from Cisco, could provide any documentation or validations on this? All of the documentation I found, including for the latest available code version still says the secondary supervisors will be powered off in stackwise-virtual configurations.

Thanks,

Romeo

[MUHAMMAD TAYYAB MUNIR]

Hi Thomas,

When your configuring the 9407 stackwise virual you already have redundancy in place and if you want to have dual supervisor module it will cost you lot and you will not get any benfits from it. it will remain power off you can power on one module at a time when you configuring in stackwise.

• Restrictions for Cisco StackWise Virtual
  • Cisco StackWise Virtual is supported only on Cisco Catalyst 9404R and Cisco Catalyst 9407R switches.
  • Cisco StackWise Virtual is supported on Cisco Catalyst 9400 Series Supervisor 1 Module (C9400-SUP-1)
  and Cisco Catalyst 9400 Series Supervisor 1XL Module (C9400-SUP-1XL). The feature requires a
  special, additional, C9400-SUP-UPG-LIC= license with Cisco Catalyst 9400 Series Supervisor 1 Module
  (C9400-SUP-1).
  • StackWise Virtual Link (SVL) connections are established only through 10G or 40G uplink ports on the
  supervisor module. You cannot establish an SVL using a 10G port on one switch and a 40G port on the
  other switch.
  • Cisco StackWise Virtual can be configured only on one supervisor module per chassis. You can install
  two supervisor modules in each chassis used in the Cisco StackWise Virtual solution. However, only
  one of the supervisor modules will be active; the other module will be powered off.
  • The Federal Information Processing Standards (FIPS) is not supported on Cisco StackWise Virtual links.
  • When deploying Cisco StackWise Virtual, ensure that VLAN ID 4094 is not used anywhere on the
  network. All inter-chassis system control communication between stack members is carried over the
  reserved VLAN ID 4094 from the global range.
  • The dual-active detection and StackWise Virtual link configuration must be performed manually and the
  device should be rebooted for the configuration changes to take effect.
  • Fast Hello dual-active detection is supported only on supervisor module ports. Enhanced PAgP dual-active
  detection is supported on supervisor module ports and line cards.

Please find the following link.

https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst9400/software/release/16-9/configuration_guide/ha/b_169_ha_9400_cg/configuring_cisco_stackwise_virtual.pdf

Hope response was helpful for you!

BR

Tayyab

[Krishna Dhar Dubedi]

Quad-Supervisor Stackwise Virtual setup can be configured on any Catalyst 9600 chassis running IOS XE version 17.2.X or higher.

Reference - https://www.cisco.com/c/en/us/support/docs/switches/catalyst-9600-series-switches/215627-catalyst-9600-migration-to-quad-superv.html

Though this document relates to 9600 model, but since 9400 and 9600 are part of same family of 9000 switches, it is likely that quad sup SVL is now supported on 9400 as well, as 17.2.x has been long out. Your Cisco solution engineer may confirm.

HTH

Krishna

[bmckamey]

For Stackwise SVL, the 9400 & 9500 supports only 1 sup per chassis, whereas the 9600 supports 2 sups per chassis. Please see the link below and the quote from it. Cheers!

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

"StackWise Virtual is also supported on all Catalyst 9400 models - C9404, C9407 and C9410 chassis, with support of only single supervisor placed in the same slot number of both the StackWise virtual participating chassis. Catalyst 9400 can be deployed with all types of supervisor modules but SUP-1 module requires an additional License for StackWise virtual configuration. The in-chassis standby Supervisors if available will be powered-off by the system during the StackWise Virtual conversion. In the event of failure, the failed supervisor has to be manually replaced. This limitation will be removed in the future software release."

No release currently supports at this time that i'm aware of for the Stackwise SVL scenario with 9400/9500's and QUAD sups