Configuration

All flags, environment variables, ConfigMap settings, and tuning guidance for unbounded-net.

This document describes all configuration options for unbounded-net components. For a conceptual introduction, see Networking Concepts.

Runtime Configuration

Both the controller and node agent load runtime settings from a shared YAML file mounted from the unbounded-net-config ConfigMap.

• Default path: /etc/unbounded-net/config.yaml
• Override: --config-file=<path>
• Startup behavior: fail-fast if the config file is missing or invalid.
• CLI flags still work as explicit overrides when set.

Config Structure

common:
  azureTenantId: ""           # Only for Azure Portal links in the UI
  apiserverURL: ""            # Override API server URL (empty = in-cluster)
  logLevel: 2                 # klog verbosity (0-10), watched for live changes

controller:
  healthPort: 9999
  nodeAgentHealthPort: 9998
  informerResyncPeriod: 300s
  statusStaleThreshold: 40s
  registerAggregatedAPIServer: true
  leaderElection:
    enabled: true
    leaseDuration: 15s
    renewDeadline: 5s
    retryPeriod: 10s

node:
  cniConfDir: /host/etc/cni/net.d
  cniConfFile: 10-unbounded.conflist
  bridgeName: cbr0
  wireGuardDir: /host/etc/wireguard
  wireGuardPort: 51820
  mtu: 1280
  healthPort: 9998
  tunnelDataplaneMapSize: 16384
  tunnelIPFamily: IPv4
  preferredPrivateEncap: GENEVE
  preferredPublicEncap: WireGuard
  genevePort: 6081
  geneveVni: 1
  vxlanPort: 4789

Controller Configuration

Leader Election

Health and Monitoring

Logging

Node Agent Configuration

General

CNI Configuration

MTU Guidance

The node.mtu setting controls the MTU on tunnel and bridge interfaces. Encapsulation overhead:

Formula: node.mtu = <lowest physical-link MTU> - 80

Using 80 (the largest overhead) ensures the value is safe for all tunnel types. For standard 1500-byte links: 1500 - 80 = 1420.

Behavior:

• Each node agent detects its default-route interface MTU and annotates itself with net.unbounded-cloud.io/tunnel-mtu.
• Effective MTU = min(configured MTU, detected MTU).
• If configured MTU exceeds detected, the node logs an error and surfaces an mtuMismatch status error.
• A value of 0 is normalized to 1280.

WireGuard

GENEVE

VXLAN

The narrow source port range (32 ports) limits distinct flows from VMs, helping avoid flow table limits on cloud platforms (e.g., Azure).

IPIP

Tunnel interface names

The three shared tunnel device names (geneve0, vxlan0, ipip0) and the per-port WireGuard interface prefix (default wg) are configurable via the flags above and via the matching YAML fields under node: (geneveInterfaceName, vxlanInterfaceName, ipipInterfaceName, wireGuardInterfacePrefix). Operators rarely need to change them.

Constraints, enforced at startup:

• Shared tunnel names: non-empty, at most 15 bytes (Linux IFNAMSIZ limit), pairwise distinct, must not equal unbounded0.
• WireGuard prefix: non-empty, at most 10 bytes (so prefix + 5-digit UDP port fits in IFNAMSIZ), no /, must not equal unbounded0.
• unbounded0 (the agent’s eBPF dummy device) is not configurable.

When the names are changed, the agent automatically removes previous-run devices it can confidently identify, scoped narrowly so other CNIs (e.g. Cilium) running flow-based GENEVE / VXLAN on different UDP ports are not touched. IPIP is not auto-cleaned: remove a renamed-away IPIP device manually with ip link del <old-name>.

Tunnel Dataplane

The node agent uses an eBPF dataplane: BPF LPM tries on the unbounded0 interface drive per-destination tunnel redirection.

Tunnel Protocol Selection

The tunnelProtocol field is available on all scope CRDs:

When Auto, links using external IPs use WireGuard; internal-only links use the preferred private encap (default GENEVE). The security-wins rule ensures WireGuard is used if any scope explicitly requests it.

See Routing Flows for the full protocol selection algorithm.

Status Push

Health Check (UDP Probes)

Health check sessions are automatically created for all routes with nexthops. Route metric adjustment on failure provides fast failover.

Firewall Requirements

Resource Requirements

Controller

resources:
  requests: { cpu: 10m, memory: 64Mi }
  limits:   { cpu: 100m, memory: 128Mi }

Node Agent

resources:
  requests: { cpu: 10m, memory: 32Mi }
  limits:   { cpu: 100m, memory: 64Mi }

Scaling

Environment Variables

Controller

Node Agent

Tuning Recommendations

High Availability

replicas: 2
args:
  - --leader-elect=true
  - --leader-elect-lease-duration=15s
  - --leader-elect-renew-deadline=5s

Large Clusters (1000+ nodes)

# Controller
args:
  - --informer-resync-period=600s

# Node agent
args:
  - --informer-resync-period=7200s

Next Steps

• Custom Resources – CRD specifications.
• Routing Flows – Packet-level routing details.
• Operations – Deployment, monitoring, and troubleshooting.