// Technical guide // Network · SDN Fabrics

SDN Fabrics
in Proxmox VE

Fabrics, introduced in Proxmox VE 9, are a mechanism that automates routing between cluster nodes. It configures routing protocols on the physical interfaces and builds a routed underlay — the foundation for a full-mesh Ceph network and for EVPN/VXLAN overlays.

// Table of Contents
  1. Automatic routed underlay
  2. Two protocols to choose from
  3. A fabric step by step
  4. Full-mesh for Ceph and EVPN
// 01 · What a fabric is

Automatic routed underlay

Instead of hand-configuring routing on every node, you define a fabric — a logical layer that sets up the routing protocol on chosen interfaces and provides L3 connectivity between cluster nodes. On that routed base you then run Ceph traffic or an EVPN/VXLAN overlay.

ℹ️

Fabrics use the FRR implementation — make sure the frr and frr-pythontools packages are installed.

// 02 · OpenFabric vs OSPF

Two protocols to choose from

A fabric can run on one of two routing protocols (both from the FRR suite):

Each node in a fabric needs a unique router-ID (e.g. 192.0.2.1) — its identity in the routing domain.

// 03 · Configuration

A fabric step by step

You set it all up from the UI — no hand-editing FRR files:

StepWhere / what
Create a fabricDatacenter → SDN → Fabrics → "Add Fabric", pick the protocol
Add nodesuse the "+" button to select nodes and the interfaces linking them
Router-IDgive each node a unique router-ID
ApplySDN → Apply — the routing config rolls out across the cluster
// 04 · Use cases

Full-mesh for Ceph and EVPN

💡

Meshing 3 nodes over a fabric gives a cheap, fast Ceph backend without an expensive 100GbE switch in the middle — a popular choice when consolidating after a VMware migration.

We'll design the SDN network in your cluster

We'll plan the fabric (OpenFabric/OSPF), a full-mesh for Ceph and an EVPN/VXLAN overlay — cleanly and with performance in mind after a VMware migration.

⚡ Free consultation → WireGuard & BGP in SDN