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tun

tun:
  disabled: false
  dev: nebula1
  drop_local_broadcast: false
  drop_multicast: false
  tx_queue: 500
  mtu: 1300
  routes:
    - mtu: 8800
      route: 10.0.0.0/16
  unsafe_routes:
    - route: 172.16.1.0/24
      via: 192.168.100.99
      mtu: 1300 # mtu will default to tun mtu if this option is not specified
      install: true # controls whether this route is installed in the systems routing table.

tun.disabled​

Default: False

Allows the nebula interface (tun) to be disabled, which lets you run a lighthouse without a nebula interface (and therefore without root). You will not be able to communiate over IP with a nebula node that uses this setting.

tun.dev​

dev sets the interface name for your nebula interface. If not set, a default will be chosen by the OS. For macOS: Not required. If set, must be in the form utun[0-9]+. For FreeBSD: Required to be set, must be in the form tun[0-9]+.

tun.drop_local_broadcast​

Default: False

Toggles forwarding of local broadcast packets, the address of which depends on the ip/mask encoded in pki.cert

tun.drop_multicast​

Default: False

Toggles forwarding of multicast packets

tun.tx_queue​

Default: 500

Sets the transmit queue length, if you notice lots of transmit drops on the tun it may help to raise this number. Default is 500.

tun.mtu​

Default: 1300

Default MTU for every packet, safe setting is (and the default) 1300 for internet routed packets.

tun.routes​

Route based MTU overrides. If you have known VPN IP paths that can support larger MTUs you can increase/decrease them here.

tun:
  routes:
    - mtu: 8800
      route: 10.0.0.0/16

tun.unsafe_routes​

warning

The nebula certificate of the via node MUST have the route defined as a subnet in its certificate or it will refuse to route traffic.

Unsafe routes allows you to route traffic over nebula to non-nebula nodes. Unsafe routes should be avoided unless you have hosts/services that cannot run nebula.

tun:
  unsafe_routes:
    - route: 172.16.1.0/24
      via: 192.168.100.99
      mtu: 1300
      metric: 100
      install: true # controls whether this route is installed in the systems routing table.

tun.use_system_route_table​

Default: False

On Linux only, set to true to manage unsafe routes directly on the system route table with gateway routes instead of in nebula configuration files.