High Availability on Cisco Catalyst 9300X Series Switches With mixed mode stacking available on Cisco Catalyst 9300X Series Switches, the active and standby devices use the 1+1 redundancy for application hosting. Mixed mode support is when different model variants and different network modules are used in a stack. When Cisco Catalyst 9300X Series Switches and Cisco Catalyst 9300 Series Switches are stacked, one of the two front-panel ports on Cisco Catalyst 9300X Series Switches are dynamically disabled. Only the AppGigabitEthernet 1/0/1 interface is displayed as enabled. This section describes some of the high availability scenarios:
Application Hosting High Availability on Cisco Catalyst 9300X Series Switches Scenario Supported/Unsupported Single application in trunk and access modes, and front-panel ports with an overlapping VLAN. Not a valid configuration. The same VLAN is configured in trunk mode and access mode. Because of the configuration, the VLAN overlaps with both ports. Multiple application in trunk mode. Not a valid configuration. The traffic is not isolated. Two applications, one in trunk mode and the other in access mode. Not a valid configuration. Overlapping VLAN.
Stack Mode Apps Ports Used Behavior Cisco Catalyst 9300X Series Switch active + Cisco Catalyst 9300X Series Switch standby 2 1 Supported Cisco Catalyst 9300X Series Switch active + Cisco Catalyst 9300X Series Switch standby 1 1 Supported Cisco Catalyst 9300X Series Switch active + Cisco Catalyst 9300 Series Switch standby 1 1 Only if port 1 is used. Supported. This configuration is supported, if port 1 is configured by using the app-vnic Appgigabitethernet port 1 trunk or the app-vnic AppgigabitEthernet trunk commands. If a port number is not specified, the default port 1 is used, when a switchover happens. Application Hosting 6