radvd

Manage radvd (Router Advertisement Daemon) configuration.

This role provides IPv6 Router Advertisements for network interfaces, enabling Stateless Address Autoconfiguration (SLAAC) and/or DHCPv6.

Privilege escalation

Package installation
Writing in protected locations /etc/radvd.conf, /etc/cifmw-radvd.d
Managing system service radvd.service

Common Parameters

cifmw_radvd_basedir: (String) Configuration fragments directory. Defaults to /etc/cifmw-radvd.d.
cifmw_radvd_networks: (List) List of networks to configure. Defaults to [].
cifmw_radvd_remove_package: (Bool) Remove the radvd package during cleanup. Defaults to false.

Network Configuration

Each network in cifmw_radvd_networks supports the following parameters:

name: (String) Network/interface name. Required.
state: (String) Network status. Must be either present or absent. Defaults to present.
prefixes: (List[mapping]) List of IPv6 prefixes to advertise. Required when state is present.
adv_send_advert: (Bool) Enable/disable router advertisements. Defaults to true.
adv_managed_flag: (Bool) Managed address configuration flag (M-flag). Indicates DHCPv6 for addresses.
adv_other_config_flag: (Bool) Other configuration flag (O-flag). Indicates DHCPv6 for other configuration.
adv_ra_solicited_unicast: (Bool) Enable unicast router advertisements.
adv_link_mtu: (Int) Advertised MTU for the link.
min_rtr_adv_interval: (Int) Minimum router advertisement interval in seconds.
max_rtr_adv_interval: (Int) Maximum router advertisement interval in seconds.
routes: (List[mapping]) List of routes to advertise. Optional.
rdnss: (List[mapping]) List of recursive DNS servers to advertise. Optional.

Prefix mapping

network: (String) IPv6 prefix (e.g., 2001:db8:1::/64). Required.
adv_on_link: (Bool) On-link flag. Defaults to true.
adv_autonomous: (Bool) Autonomous address configuration flag (SLAAC). Defaults to true.
adv_router_addr: (Bool) Include router address in prefix information.
adv_valid_lifetime: (String/Int) Valid lifetime for the prefix (e.g., 86400, infinity).
adv_preferred_lifetime: (String/Int) Preferred lifetime for the prefix.

Route mapping

network: (String) IPv6 route prefix. Required.
adv_route_preference: (String) Route preference (low, medium, high).
adv_route_lifetime: (Int) Route lifetime in seconds.

RDNSS mapping

servers: (List[String]) List of IPv6 DNS server addresses. Required.
adv_rdnss_lifetime: (Int) RDNSS lifetime in seconds.

Examples

Basic network with SLAAC only

- name: Configure radvd networks
  vars:
    cifmw_radvd_networks:
      - name: testnet
        adv_managed_flag: false
        adv_other_config_flag: false
        adv_link_mtu: 1500
        min_rtr_adv_interval: 30
        max_rtr_adv_interval: 100
        prefixes:
          - network: "2001:db8:1::/64"
            adv_on_link: true
            adv_autonomous: true
            adv_router_addr: true
  ansible.builtin.include_role:
    name: radvd

Network with DHCPv6 for addresses and other configuration

- name: Configure radvd with DHCPv6
  vars:
    cifmw_radvd_networks:
      - name: provisioning
        adv_managed_flag: true
        adv_other_config_flag: true
        adv_ra_solicited_unicast: true
        adv_link_mtu: 1500
        min_rtr_adv_interval: 30
        max_rtr_adv_interval: 100
        prefixes:
          - network: "2001:db8:2::/64"
            adv_on_link: true
            adv_autonomous: false
        rdnss:
          - servers:
              - "2001:db8:2::53"
            adv_rdnss_lifetime: 300
  ansible.builtin.include_role:
    name: radvd

Multiple networks

- name: Configure multiple networks
  vars:
    cifmw_radvd_networks:
      - name: net1
        adv_managed_flag: true
        adv_other_config_flag: true
        adv_link_mtu: 1500
        min_rtr_adv_interval: 30
        max_rtr_adv_interval: 100
        prefixes:
          - network: "2001:db8:1::/64"
            adv_on_link: true
            adv_autonomous: true
      - name: net2
        adv_managed_flag: false
        adv_other_config_flag: false
        prefixes:
          - network: "2001:db8:2::/64"
            adv_on_link: true
            adv_autonomous: true
  ansible.builtin.include_role:
    name: radvd

Remove a network configuration

- name: Remove radvd configuration for a network
  vars:
    cifmw_radvd_networks:
      - name: testnet
        state: absent
  ansible.builtin.include_role:
    name: radvd

Cleanup entire radvd service

- name: Cleanup radvd
  vars:
    # Set to true to also remove the radvd package (default: false)
    cifmw_radvd_remove_package: false
  ansible.builtin.include_role:
    name: radvd
    tasks_from: cleanup.yml

Understanding the flags

Managed Flag (M-flag) - `adv_managed_flag`

When set to true, hosts should use DHCPv6 to obtain IPv6 addresses (stateful DHCPv6). When set to false, hosts should use SLAAC (Stateless Address Autoconfiguration) based on the advertised prefix.

Other Config Flag (O-flag) - `adv_other_config_flag`

When set to true, hosts should use DHCPv6 to obtain other configuration information (DNS, NTP, etc.).

Common configurations

SLAAC only: adv_managed_flag: false, adv_other_config_flag: false, adv_autonomous: true
SLAAC + DHCPv6 for options: adv_managed_flag: false, adv_other_config_flag: true, adv_autonomous: true
DHCPv6 for everything: adv_managed_flag: true, adv_other_config_flag: true, adv_autonomous: false

Notes

The interface/bridge specified by the name parameter must exist before radvd can advertise on it.
IPv6 forwarding must be enabled on the host for router advertisements to work properly.
Multiple prefixes can be advertised on the same interface.
The role uses the system radvd.service from the RPM package.
Configuration is assembled from fragments in /etc/cifmw-radvd.d/ into /etc/radvd.conf.