Fabric in a Box initial configuration

Se1r — Thu, 08 May 2025 11:48:07 GMT

Hello,

I would like to ask what is the required configuration for deploying a switch in Fabric-in-a-Box (FIAB) mode (just one stack of two switches, with no downlinks connected).

I see that, in order to declare it as CP/BN/Edge in the Fabric Site Catalyst Center GUI, the only requirement is that the Loopback0 interface is created with an IP address and reachable by Catalyst Center.

Once that’s done, Catalyst Center automatically deploys the full configuration, and the switch is assigned all three roles (CP/BN/Edge).

From what I understand, there’s no need to manually configure anything else beyond what I mentioned. However, I’ve noticed that a standalone FIAB switch using the Loopback0 IP doesn’t seem to have IS-IS declared, nor is the MTU set to 1492.

Is this correct?

Thanks!

Re: Fabric in a Box initial configuration

Andrii Oliinyk — Thu, 08 May 2025 12:08:18 GMT

answer to your Q is: IS-IS (basically whatever IGP) is not needed until there is >1 node in the Fabric.
IS-IS will be automatically configured when u LAN-A your ENs.
Keep in mind on BN you have to configure L3-handoff. There are some caveats: f.e. u cannot automate l3-handoff in the same VLAN to peer with 2 FNs which otherwise would be usual practice for CPE to peer with 2 PEs.

topic Fabric in a Box initial configuration in Software-Defined Access (SD-Access)

Fabric in a Box initial configuration

Re: Fabric in a Box initial configuration