# Networking

## pve1 as built (Stage 1, current)

Single NIC (2.5GbE), single bridge `vmbr0` on the flat LAN
(`192.168.2.0/24`), no VLANs. There is no corosync or Ceph traffic to
separate yet — this node isn't clustered. Segmentation for Stage 1 is
done at the firewall, not the network: `scripts/deploy-firewall.sh`
restricts SSH (22) and the web UI (8006) to the management CIDR via the
PVE datacenter firewall (default-deny inbound otherwise). That's
sufficient until Stage 2 needs actual separate physical/VLAN paths for
corosync and Ceph traffic — see below.

## pve-test as built (sandbox, current)

Different node, different design, not a Stage 1/2 example to generalize
from: `pve-test` runs `vmbr0` bridged over a wifi NIC in 4addr client mode
(active-backup bonded with a wired NIC as an automatic fallback). Full
detail, including why this is normally impossible and how it was
validated before trusting it with the management IP, in
`06-pve-test-wifi-network.md`. This is intentionally a one-off for a
standalone sandbox box — never extend it to a node that's clustered or
Ceph-connected (see the Stage 2 note in `00-overview.md`).

## Target design (Stage 2, future cluster)

## Required separation

Keep these on logically separate networks/VLANs, ideally separate NICs:

- **Management** — web UI (8006), SSH
- **Corosync** — cluster quorum. Low, *consistent* latency (well under
  5ms) matters more than bandwidth. Never share with VM/storage traffic.
- **Ceph public** — VM-to-OSD traffic (once Ceph is live)
- **Ceph cluster/backend** — OSD-to-OSD replication, heaviest load

## Practical layout

2x 10/25GbE bonded or split:

- Link pair A → Ceph (public + backend, or split further if 4 NICs
  available)
- Link pair B → management + corosync + VM traffic, with corosync on its
  own VLAN even when sharing a physical NIC with the rest

## Cluster join requirements

- All nodes reachable to each other on SSH (22) and the corosync network
- Same PVE version across nodes
- NTP-synced clocks

## Firewall

Proxmox's built-in firewall operates at datacenter and node level.
Default-deny, then whitelist:

- SSH from the management network/VLAN only
- Web UI (8006) from the management network/VLAN only
- Corosync ports between cluster nodes
- Ceph ports between cluster nodes (once Ceph is live)

Enforce the network separation above at the firewall — corosync and Ceph
traffic shouldn't be reachable from the VM network even if they end up
sharing a physical link.

See `config/pve-firewall/` for a starting rule set.