nebula/examples/config.yml

# This is the nebula example configuration file. You must edit, at a minimum, the static_host_map, lighthouse, and firewall sections
# Some options in this file are HUPable, including the pki section. (A HUP will reload credentials from disk without affecting existing tunnels)

# PKI defines the location of credentials for this node. Each of these can also be inlined by using the yaml ": |" syntax.
pki:
  # The CAs that are accepted by this node. Must contain one or more certificates created by 'nebula-cert ca'
  ca: /etc/nebula/ca.crt
  cert: /etc/nebula/host.crt
  key: /etc/nebula/host.key
  # blocklist is a list of certificate fingerprints that we will refuse to talk to
  #blocklist:
  #  - c99d4e650533b92061b09918e838a5a0a6aaee21eed1d12fd937682865936c72
  # disconnect_invalid is a toggle to force a client to be disconnected if the certificate is expired or invalid.
  #disconnect_invalid: true

  # initiating_version controls which certificate version is used when initiating handshakes.
  # This setting only applies if both a v1 and a v2 certificate are configured, in which case it will default to `1`.
  # Once all hosts in the mesh are configured with both a v1 and v2 certificate then this should be changed to `2`.
  # After all hosts in the mesh are using a v2 certificate then v1 certificates are no longer needed.
  # initiating_version: 1

# The static host map defines a set of hosts with fixed IP addresses on the internet (or any network).
# A host can have multiple fixed IP addresses defined here, and nebula will try each when establishing a tunnel.
# The syntax is:
#   "{nebula ip}": ["{routable ip/dns name}:{routable port}"]
# Example, if your lighthouse has the nebula IP of 192.168.100.1 and has the real ip address of 100.64.22.11 and runs on port 4242:
static_host_map:
  "192.168.100.1": ["100.64.22.11:4242"]

# The static_map config stanza can be used to configure how the static_host_map behaves.
#static_map:
  # cadence determines how frequently DNS is re-queried for updated IP addresses when a static_host_map entry contains
  # a DNS name.
  #cadence: 30s

  # network determines the type of IP addresses to ask the DNS server for. The default is "ip4" because nodes typically
  # do not know their public IPv4 address. Connecting to the Lighthouse via IPv4 allows the Lighthouse to detect the
  # public address. Other valid options are "ip6" and "ip" (returns both.)
  #network: ip4

  # lookup_timeout is the DNS query timeout.
  #lookup_timeout: 250ms

lighthouse:
  # am_lighthouse is used to enable lighthouse functionality for a node. This should ONLY be true on nodes
  # you have configured to be lighthouses in your network
  am_lighthouse: false
  # serve_dns optionally starts a dns listener that responds to various queries and can even be
  # delegated to for resolution
  #serve_dns: false
  #dns:
    # The DNS host defines the IP to bind the dns listener to. This also allows binding to the nebula node IP.
    #host: 0.0.0.0
    #port: 53
  # interval is the number of seconds between updates from this node to a lighthouse.
  # during updates, a node sends information about its current IP addresses to each node.
  interval: 60
  # hosts is a list of lighthouse hosts this node should report to and query from
  # IMPORTANT: THIS SHOULD BE EMPTY ON LIGHTHOUSE NODES
  # IMPORTANT2: THIS SHOULD BE LIGHTHOUSES' NEBULA IPs, NOT LIGHTHOUSES' REAL ROUTABLE IPs
  hosts:
    - "192.168.100.1"

  # remote_allow_list allows you to control ip ranges that this node will
  # consider when handshaking to another node. By default, any remote IPs are
  # allowed. You can provide CIDRs here with `true` to allow and `false` to
  # deny. The most specific CIDR rule applies to each remote. If all rules are
  # "allow", the default will be "deny", and vice-versa. If both "allow" and
  # "deny" IPv4 rules are present, then you MUST set a rule for "0.0.0.0/0" as
  # the default. Similarly if both "allow" and "deny" IPv6 rules are present,
  # then you MUST set a rule for "::/0" as the default.
  #remote_allow_list:
    # Example to block IPs from this subnet from being used for remote IPs.
    #"172.16.0.0/12": false

    # A more complicated example, allow public IPs but only private IPs from a specific subnet
    #"0.0.0.0/0": true
    #"10.0.0.0/8": false
    #"10.42.42.0/24": true

  # EXPERIMENTAL: This option may change or disappear in the future.
  # Optionally allows the definition of remote_allow_list blocks
  # specific to an inside VPN IP CIDR.
  #remote_allow_ranges:
    # This rule would only allow only private IPs for this VPN range
    #"10.42.42.0/24":
      #"192.168.0.0/16": true

  # local_allow_list allows you to filter which local IP addresses we advertise
  # to the lighthouses. This uses the same logic as `remote_allow_list`, but
  # additionally, you can specify an `interfaces` map of regular expressions
  # to match against interface names. The regexp must match the entire name.
  # All interface rules must be either true or false (and the default will be
  # the inverse). CIDR rules are matched after interface name rules.
  # Default is all local IP addresses.
  #local_allow_list:
    # Example to block tun0 and all docker interfaces.
    #interfaces:
      #tun0: false
      #'docker.*': false
    # Example to only advertise this subnet to the lighthouse.
    #"10.0.0.0/8": true

  # advertise_addrs are routable addresses that will be included along with discovered addresses to report to the
  # lighthouse, the format is "ip:port". `port` can be `0`, in which case the actual listening port will be used in its
  # place, useful if `listen.port` is set to 0.
  # This option is mainly useful when there are static ip addresses the host can be reached at that nebula can not
  # typically discover on its own. Examples being port forwarding or multiple paths to the internet.
  #advertise_addrs:
    #- "1.1.1.1:4242"
    #- "1.2.3.4:0" # port will be replaced with the real listening port

  # EXPERIMENTAL: This option may change or disappear in the future.
  # This setting allows us to "guess" what the remote might be for a host
  # while we wait for the lighthouse response.
  #calculated_remotes:
    # For any Nebula IPs in 10.0.10.0/24, this will apply the mask and add
    # the calculated IP as an initial remote (while we wait for the response
    # from the lighthouse). Both CIDRs must have the same mask size.
    # For example, Nebula IP 10.0.10.123 will have a calculated remote of
    # 192.168.1.123
    #10.0.10.0/24:
      #- mask: 192.168.1.0/24
      #  port: 4242

# Port Nebula will be listening on. The default here is 4242. For a lighthouse node, the port should be defined,
# however using port 0 will dynamically assign a port and is recommended for roaming nodes.
listen:
  # To listen on only ipv4, use "0.0.0.0"
  host: "::"
  port: 4242
  # Sets the max number of packets to pull from the kernel for each syscall (under systems that support recvmmsg)
  # default is 64, does not support reload
  # Note: on Linux with UDP GRO (kernel 5.10+), each receive slot is sized for a full 64KiB coalesced
  # superpacket, so the receive scratch is batch * 64KiB per listening socket (~4MiB per routine at the
  # default of 64). Lower this to trade peak per-syscall throughput for memory on constrained hosts.
  #batch: 64
  # Linux only. Configure socket buffers for the udp side (outside), leave unset to use the system defaults. Values will be doubled by the kernel
  # Default is net.core.rmem_default and net.core.wmem_default (/proc/sys/net/core/rmem_default and /proc/sys/net/core/rmem_default)
  # Maximum is limited by memory in the system, SO_RCVBUFFORCE and SO_SNDBUFFORCE is used to avoid having to raise the system wide
  # max, net.core.rmem_max and net.core.wmem_max
  read_buffer: 3412512
  write_buffer: 3412512

  # On Windows only
  # When true, Nebula installs a WFP (Windows Filtering Platform) PERMIT filter scoped to UDP at the listener port.
  # WFP sits below Windows Defender Firewall, so this lets peer handshakes reach Nebula's outside socket regardless
  # of WDF's inbound rules.
  # Default true; set to false to leave WDF in charge of inbound decisions on the listener port. Not reloadable.
  #windows_bypass_wdf: true

  # On macOS only
  # macOS scopes the udp socket to the interface it was created on, so moving between networks (wifi to wired,
  # office to home) leaves Nebula sending out an interface that no longer has a route. When true, Nebula watches
  # the routing socket and rebinds the listener once the change settles.
  # iOS does not use this, the host app drives the same rebind itself.
  # Default true. Not reloadable.
  #rebind_on_network_change: true

  # By default, Nebula replies to packets it has no tunnel for with a "recv_error" packet. This packet helps speed up reconnection
  # in the case that Nebula on either side did not shut down cleanly. This response can be abused as a way to discover if Nebula is running
  # on a host though. This option lets you configure if you want to send "recv_error" packets always, never, or only to private network remotes.
  # valid values: always, never, private
  # This setting is reloadable.
  #send_recv_error: always
  # Similar to send_recv_error, this option lets you configure if you want to accept "recv_error" packets from remote hosts.
  # valid values: always, never, private
  # This setting is reloadable.
  #accept_recv_error: always
  # The so_sock option is a Linux-specific feature that allows all outgoing Nebula packets to be tagged with a specific identifier.
  # This tagging enables IP rule-based filtering. For example, it supports 0.0.0.0/0 unsafe_routes,
  # allowing for more precise routing decisions based on the packet tags. Default is 0 meaning no mark is set.
  # This setting is reloadable.
  #so_mark: 0
  # the udp_offloads setting controls if Nebula will attempt to enable GSO and GRO for its UDP socket(s). Linux only, not reloadable.
  # udp_offloads: false

# Routines is the number of thread pairs to run that consume from the tun and UDP queues.
# Currently, this defaults to 1 which means we have 1 tun queue reader and 1
# UDP queue reader. Setting this above one will set IFF_MULTI_QUEUE on the tun
# device and SO_REUSEPORT on the UDP socket to allow multiple queues.
# This option is only supported on Linux.
#routines: 1

punchy:
  # Continues to punch inbound/outbound at a regular interval to avoid expiration of firewall nat mappings
  # This setting is reloadable.
  punch: true

  # respond means that a node you are trying to reach will connect back out to you if your hole punching fails
  # this is extremely useful if one node is behind a difficult nat, such as a symmetric NAT
  # Default is false
  # This setting is reloadable.
  #respond: true

  # delays a punch response for misbehaving NATs, default is 1 second.
  # This setting is reloadable.
  #delay: 1s

  # set the delay before attempting punchy.respond. Default is 5 seconds. respond must be true to take effect.
  # This setting is reloadable.
  #respond_delay: 5s

# Cipher allows you to choose between the available ciphers for your network. Options are chachapoly or aes
# IMPORTANT: this value must be identical on ALL NODES/LIGHTHOUSES. We do not/will not support use of different ciphers simultaneously!
#cipher: aes

# Preferred ranges is used to define a hint about the local network ranges, which speeds up discovering the fastest
# path to a network adjacent nebula node.
# This setting is reloadable.
#preferred_ranges: ["172.16.0.0/24"]

# sshd can expose informational and administrative functions via ssh. This can expose informational and administrative
# functions, and allows manual tweaking of various network settings when debugging or testing.
#sshd:
  # Toggles the feature
  #enabled: true
  # Host and port to listen on, port 22 is not allowed for your safety
  #listen: 127.0.0.1:2222
  # A file containing the ssh host private key to use
  # A decent way to generate one: ssh-keygen -t ed25519 -f ssh_host_ed25519_key -N "" < /dev/null
  #host_key: ./ssh_host_ed25519_key
  # Authorized users and their public keys
  #authorized_users:
    #- user: steeeeve
      # keys can be an array of strings or single string
      #keys:
        #- "ssh public key string"
  # Trusted SSH CA public keys. These are the public keys of the CAs that are allowed to sign SSH keys for access.
  #trusted_cas:
    #- "ssh public key string"
  # sandbox_dir restricts file paths for profiling commands (start-cpu-profile, save-heap-profile,
  # save-mutex-profile) to the specified directory. Relative paths will be resolved within this directory,
  # and absolute paths outside of it will be rejected. Default is $TMP/nebula-debug.
  # The directory is NOT automatically created.
  # Overriding this to "" is the same as "/" and will allow overwriting any path on the host.
  #sandbox_dir: /var/tmp/nebula-debug

# EXPERIMENTAL: relay support for networks that can't establish direct connections.
relay:
  # Relays are a list of Nebula IP's that peers can use to relay packets to me.
  # IPs in this list must have am_relay set to true in their configs, otherwise
  # they will reject relay requests.
  #relays:
    #- 192.168.100.1
    #- <other Nebula VPN IPs of hosts used as relays to access me>
  # Set am_relay to true to permit other hosts to list my IP in their relays config. Default false.
  am_relay: false
  # Set use_relays to false to prevent this instance from attempting to establish connections through relays.
  # default true
  use_relays: true

# Configure the private interface. Note: addr is baked into the nebula certificate
tun:
  # When tun is disabled, a lighthouse can be started without a local tun interface (and therefore without root)
  disabled: false
  # Name of the device. If not set, a default will be chosen by the OS.
  # For macOS: if set, must be in the form `utun[0-9]+`.
  # For NetBSD: Required to be set, must be in the form `tun[0-9]+`
  dev: nebula1
  # Toggles forwarding of local broadcast packets, the address of which depends on the ip/mask encoded in pki.cert
  drop_local_broadcast: false
  # Toggles forwarding of multicast packets
  drop_multicast: false
  # Sets the transmit queue length, if you notice lots of transmit drops on the tun it may help to raise this number. Default is 5000
  tx_queue: 5000
  # Default MTU for every packet, safe setting is (and the default) 1300 for internet based traffic
  # Anything above 8937, here or on a route below, is capped to 8937 with a warning
  mtu: 1300

  # the use_offloads setting controls if Nebula will attempt to enable GSO and GRO for the tun device. Linux only, not reloadable.
  #use_offloads: false

  # Linux only. pin_threads pins each tun reader/encrypt OS thread to a single CPU. This keeps every goroutine's
  # batched sends flowing through one XPS-selected NIC TX ring, so packets within a flow stay ordered on the wire
  # instead of being sprayed across multiple TX rings and reordered. Not reloadable. Coerced to false if routines <= 1.
  #pin_threads: true

  # pin_threads_key helps the CPU-auto-selector shuffle which CPUs are chosen for pinning.
  # Valid options are "pid" or "port". Use "port" if you want Nebula to choose the same cores every time, which is nice for benchmarking.
  # Linux only, not reloadable.
  #pin_threads_key: "pid"

  # Linux only. cpu_affinity overrides which CPUs the tun reader threads pin to: a list of CPU IDs, one per routine
  # (see the top-level `routines` setting). Lists shorter than `routines` are modulo-cycled across the queues; extra
  # entries are ignored. IDs must be within the process's allowed CPU set, so this respects taskset / cgroup cpusets;
  # a non-integer or not-allowed entry disables the override, leaving the default pin selection described below.
  # Only meaningful while pin_threads is true. Not reloadable.
  # When unset (or rejected), the default spread prefers performance cores on heterogeneous CPUs (ARM big.LITTLE,
  # Intel P/E hybrids, AMD compact cores), keeps all readers on one NUMA node and on distinct physical cores when the
  # topology allows (SMT siblings last), leaves CPU 0's physical core as a last resort, and rotates its starting
  # point per instance (keyed by the bound UDP port) so co-located nebulas don't stack their readers onto the
  # same cores.
  #cpu_affinity:
  #  - 2
  #  - 4

  # Route based MTU overrides, you have known vpn ip paths that can support larger MTUs you can increase/decrease them here
  routes:
    #- mtu: 8800
    #  route: 10.0.0.0/16

  # 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
  # Supports weighted ECMP if you define a list of gateways, this can be used for load balancing or redundancy to hosts outside of nebula
  # NOTES:
  # * You will only see a single gateway in the routing table if you are not on linux
  # * If a gateway is not reachable through the overlay another gateway will be selected to send the traffic through, ignoring weights
  #
  # unsafe_routes:
  # # Multiple gateways without defining a weight defaults to a weight of 1, this will balance traffic equally between the three gateways
  # - route: 192.168.87.0/24
  #   via:
  #     - gateway: 10.0.0.1
  #     - gateway: 10.0.0.2
  #     - gateway: 10.0.0.3
  # # Multiple gateways with a weight, this will balance traffic accordingly
  # - route: 192.168.87.0/24
  #   via:
  #     - gateway: 10.0.0.1
  #       weight: 10
  #     - gateway: 10.0.0.2
  #       weight: 5
  #
  # NOTE: The nebula certificate of the "via" node(s) *MUST* have the "route" defined as a subnet in its certificate
  # `via`: single node or list of gateways to use for this route
  # `mtu`: will default to tun mtu if this option is not specified
  # `metric`: will default to 0 if this option is not specified
  # `install`: will default to true, controls whether this route is installed in the systems routing table.
  # This setting is reloadable.
  unsafe_routes:
    #- route: 172.16.1.0/24
    #  via: 192.168.100.99
    #  mtu: 1300
    #  metric: 100
    #  install: true

  # On Windows only, sets the network category of the nebula interface. Without this, Windows often
  # leaves the network as "Unidentified" and treats it as Public, which makes the host firewall more
  # restrictive than you usually want for an overlay between trusted peers. Valid values:
  #   private             - treat the nebula network as a private/trusted network (default)
  #   public              - treat it as a public/untrusted network
  #   domain              - treat it as a domain-authenticated network
  #   unset               - leave whatever Windows decided alone
  # Not reloadable.
  #network_category: private

  # On Windows only
  # When true, Nebula installs a WFP (Windows Filtering Platform) PERMIT filter scoped to the nebula adapter LUID.
  # WFP sits below Windows Defender Firewall, so this lets inbound traffic through regardless of WDF rules.
  # Filters are auto-removed when the adapter goes away.
  # See listen.windows_bypass_wdf for the matching control over inbound to nebula's outside UDP listener.
  # Default true; set to false to leave WDF in charge of inbound decisions on the nebula interface. Not reloadable.
  #windows_bypass_wdf: true

  # 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. Default false, not reloadable.
  #use_system_route_table: false
  # Buffer size for reading routes updates. 0 means default system buffer size. (/proc/sys/net/core/rmem_default).
  # If using massive routes updates, for example BGP, you may need to increase this value to avoid packet loss.
  # SO_RCVBUFFORCE is used to avoid having to raise the system wide max
  #use_system_route_table_buffer_size: 0

# Configure logging level
logging:
  # trace, debug, info, warn, or error. Default is info and is reloadable.
  # fatal and panic are accepted for backwards compatibility and map to error.
  #NOTE: Debug and trace modes can log remotely controlled/untrusted data which can quickly fill a disk in some
  # scenarios. Debug and trace logging are also CPU intensive and will decrease performance overall.
  # Only enable debug or trace logging while actively investigating an issue.
  level: info
  # json or text formats currently available. Default is text.
  format: text
  # Disable timestamp logging. Useful when output is redirected to a logging system that already adds timestamps. Default is false.
  #disable_timestamp: true
  # Timestamps use RFC3339Nano ("2006-01-02T15:04:05.999999999Z07:00") and are not configurable.

# The stats section is reloadable. A HUP may change the backend, toggle stats
# on or off, switch the listen/host address, or pick up new DNS for the
# configured graphite host.
#stats:
  #type: graphite
  #prefix: nebula
  #protocol: tcp
  #host: 127.0.0.1:9999
  #interval: 10s

  #type: prometheus
  #listen: 127.0.0.1:8080
  #path: /metrics
  #namespace: prometheusns
  #subsystem: nebula
  #interval: 10s

  # enables counter metrics for meta packets
  #   e.g.: `messages.tx.handshake`
  # NOTE: `message.{tx,rx}.recv_error` is always emitted
  # Not reloadable.
  #message_metrics: false

  # enables detailed counter metrics for lighthouse packets
  #   e.g.: `lighthouse.rx.HostQuery`
  # Not reloadable.
  #lighthouse_metrics: false

# Handshake Manager Settings
#handshakes:
  # Handshakes are sent to all known addresses at each interval with a linear backoff,
  # Wait try_interval after the 1st attempt, 2 * try_interval after the 2nd, etc, until the handshake is older than timeout
  # A 100ms interval with the default 10 retries will give a handshake 5.5 seconds to resolve before timing out
  #try_interval: 100ms
  #retries: 20

  # query_buffer is the size of the buffer channel for querying lighthouses, drops are recorded in the lighthouse.query.dropped metric.
  #query_buffer: 1024

  # trigger_buffer is the size of the buffer channel for quickly sending handshakes
  # after receiving the response for lighthouse queries
  #trigger_buffer: 64

# Tunnel manager settings
#tunnels:
  # drop_inactive controls whether inactive tunnels are maintained or dropped after the inactive_timeout period has
  # elapsed.
  # In general, it is a good idea to enable this setting. It will be enabled by default in a future release.
  # This setting is reloadable
  #drop_inactive: false

  # inactivity_timeout controls how long a tunnel MUST NOT see any inbound or outbound traffic before being considered
  # inactive and eligible to be dropped.
  # This setting is reloadable
  #inactivity_timeout: 10m

# Nebula security group configuration
firewall:
  # Action to take when a packet is not allowed by the firewall rules.
  # Can be one of:
  #   `drop` (default): silently drop the packet.
  #   `reject`: send a reject reply.
  #     - For TCP, this will be a RST "Connection Reset" packet.
  #     - For other protocols, this will be an ICMP "Destination unreachable: Communication administratively prohibited" packet.
  outbound_action: drop
  inbound_action: drop

  # THIS FLAG IS DEPRECATED AND WILL BE REMOVED IN A FUTURE RELEASE. (Defaults to false.)
  # This setting only affects nebula hosts exposing unsafe_routes. When set to false, each inbound rule must contain a
  # `local_cidr` if the intention is to allow traffic to flow to an unsafe route. When set to true, every firewall rule
  # will apply to all configured unsafe_routes regardless of the actual destination of the packet, unless `local_cidr`
  # is explicitly defined. This is usually not the desired behavior and should be avoided!
  #default_local_cidr_any: false

  conntrack:
    tcp_timeout: 12m
    udp_timeout: 3m
    default_timeout: 10m

  # The firewall is default deny. There is no way to write a deny rule.
  # Rules are comprised of a protocol, port, and one or more of host, group, or CIDR
  # Logical evaluation is roughly: port AND proto AND (ca_sha OR ca_name) AND (host OR group OR groups OR cidr) AND (local cidr)
  # - port: Takes `0` or `any` as any, a single number `80`, a range `200-901`, or `fragment` to match second and further fragments of fragmented packets (since there is no port available).
  #   proto: `any`, `tcp`, `udp`, or `icmp`
  #          a port specification is ignored if proto is `icmp`
  #   host: `any` or a literal hostname, ie `test-host`
  #   group: `any` or a literal group name, ie `default-group`
  #   groups: Same as group but accepts a list of values. Multiple values are AND'd together and a certificate would have to contain all groups to pass
  #   cidr: a remote CIDR, `0.0.0.0/0` is any ipv4 and `::/0` is any ipv6. `any` means any ip family and address.
  #   local_cidr: a local CIDR, `0.0.0.0/0` is any ipv4 and `::/0` is any ipv6. `any` means any ip family and address.
  #     This can be used to filter destinations when using unsafe_routes.
  #     By default, this is set to only the VPN (overlay) networks assigned via the certificate networks field unless `default_local_cidr_any` is set to true.
  #     If there are unsafe_routes present in this config file, `local_cidr` should be set appropriately for the intended us case.
  #   ca_name: An issuing CA name
  #   ca_sha: An issuing CA shasum

  outbound:
    # Allow all outbound traffic from this node
    - port: any
      proto: any
      host: any

  inbound:
    # Allow icmp between any nebula hosts
    - port: any
      proto: icmp
      host: any

    # Allow tcp/443 from any host with BOTH laptop and home group
    - port: 443
      proto: tcp
      groups:
        - laptop
        - home

    # Expose a subnet (unsafe route) to hosts with the group remote_client
    # This example assume you have a subnet of 192.168.100.1/24 or larger encoded in the certificate
    - port: 8080
      proto: tcp
      group: remote_client
      local_cidr: 192.168.100.1/24