topic Re: SD-Access Critical VLAN in Software-Defined Access (SD-Access)

SD-Access Critical VLAN

Ribrahim — Sun, 28 Jun 2026 10:45:39 GMT

In SD-Access solution. In case of ISE totally down is it possible to create multiple critical vlans for each VN for example one critical vlan for users, another one for IOT devices and third one for voice.

or it must be single critical data vlan for the whole fabric, and one for Voice

also can I select any custom the vlan ID like 2200 and name name :Critical_User, not keeping the default ID and name.

Re: SD-Access Critical VLAN

balaji.bandi — Sun, 28 Jun 2026 11:28:41 GMT

You cannot create multiple critical data VLANs per Virtual Network (VN), nor can you select custom VLAN IDs or names.

SD-Access automated fabric deployment architectural design limits fallback to exactly one critical data VLAN and one critical voice VLAN per fabric site.

some reference :

https://www.ciscolive.com/c/dam/r/ciscolive/global-event/docs/2022/pdf/BRKENS-2814.pdf

Maybe you need to look for a good design with high availability, but in case Cisco ISE is fully unreachable, you should rely on Scalable Group Tags (SGTs)

https://community.cisco.com/t5/networking-knowledge-base/critical-vlan-with-sd-access/ta-p/4038644

Re: SD-Access Critical VLAN

Andrii Oliinyk — Sun, 28 Jun 2026 12:20:39 GMT

addressing your 2nd Q: yes, VLAN IDs & names are customizable.

Access Virtual Networks: Log in to the Cisco Catalyst Center GUI and navigate to Provision > SD-Access > Fabric Sites.
Select Fabric Site: Choose your specific Fabric Site where the IP pool resides.
Configure Anycast Gateway: Open the Host Onboarding tab and select Virtual Networks. Choose your target VN, then click Anycast Gateways.
Edit IP Pool: Locate your IP address pool and select Edit.
Customize Values:
- Enter your preferred VLAN ID
- Assign the custom VLAN Name.
Save & Deploy: Click Update, then Deploy to push these configurations to the Fabric Edge switches.

remember about reserved ranges.