La conectividad IPv6 desaparece repentinamente

Question

En el entorno indicado a continuación, IPv4 ronronea como un gato, pero IPv6 desaparece al poco tiempo, es decir, ni siquiera el host puede acceder a su contenedor a través de IPv6 a través de la red Docker. ¿Me he perdido algo?

Edición #1

Se reemplazó 64:ff9b:: con algo global, pero el problema persiste. El host pierde su conectividad IPv6 (pero no IPv4) con el contenedor Docker conectado directamente. Primero "No hay ruta al host", luego se agota el tiempo de espera.

libro de jugadas.yml

---
- hosts: all
  become: yes
  become_method: sudo
  tasks:
  - import_tasks: tasks/firewall.yml
  - import_tasks: tasks/router.yml
  - import_tasks: tasks/docker.yml
  - name: /usr/local/docker-services
    file:
      path: /usr/local/docker-services
      owner: root
      group: root
      mode: '0700'
      state: directory
  - name: nginx-site.conf
    copy:
      dest: /usr/local/docker-services/nginx-site.conf
      owner: root
      group: root
      mode: '0666'
      src: files/nginx-site.conf
  - name: docker-compose.yml
    copy:
      dest: /usr/local/docker-services/docker-compose.yml
      owner: root
      group: root
      mode: '0666'
      content: |
        version: '2.4'
        networks:
          ext-nginx:
            internal: true
            enable_ipv6: true
            driver_opts:
              com.docker.network.bridge.name: docker1
            ipam:
              config:
              - subnet: 192.168.234.0/30
                gateway: 192.168.234.1
              - subnet: 64:ff9b::192.168.234.0/126
                gateway: 64:ff9b::192.168.234.1
        services:
          nginx:
            container_name: nginx
            image: nginx
            restart: always
            logging:
              options:
                labels: container
            labels:
              container: nginx
            networks:
              ext-nginx:
                ipv4_address: 192.168.234.2
                ipv6_address: 64:ff9b::192.168.234.2
                priority: 1
            volumes:
            - type: bind
              source: /usr/local/docker-services/nginx-site.conf
              target: /etc/nginx/conf.d/default.conf
              read_only: true
    register: docker_compose_yml
  - name: docker-compose.service
    copy:
      dest: /etc/systemd/system/docker-compose.service
      owner: root
      group: root
      mode: '0644'
      src: files/docker-compose.service
    register: docker_compose_service
  - name: systemctl daemon-reload
    when: docker_compose_service.changed
    systemd:
      daemon_reload: yes
  - name: systemctl stop docker-compose.service
    when: >-
      docker_compose_service.changed
      or docker_compose_yml.changed
    service:
      name: docker-compose
      state: stopped
  - name: systemctl start docker-compose.service
    service:
      name: docker-compose
      state: started
      enabled: yes

tareas/firewall.yml

---
- name: Firewall rules applicator
  apt:
    name: iptables-persistent
- name: Firewall rules file
  loop: [4, 6]
  copy:
    dest: '/etc/iptables/rules.v{{ item }}'
    owner: root
    group: root
    mode: '0644'
    src: 'files/firewall/rules.v{{ item }}'
  register: firewall_file
- name: Apply firewall rules
  when: 'firewall_file.results[0].changed or firewall_file.results[1].changed'
  service:
    name: netfilter-persistent
    state: restarted

tareas/enrutador.yml

---
- name: net.ipv4.ip_forward
  sysctl:
    name: net.ipv4.ip_forward
    value: '1'
- name: net.ipv6.conf.all.forwarding
  sysctl:
    name: net.ipv6.conf.all.forwarding
    value: '1'

tareas/docker.yml

---
- name: apt-transport-https
  apt:
    name: apt-transport-https
- name: Docker apt key
  apt_key:
    url: https://download.docker.com/linux/debian/gpg
- name: Docker apt repo
  apt_repository:
    filename: docker
    repo: >
      deb https://download.docker.com/linux/debian
      {{ ansible_lsb.codename }} stable
- name: /etc/docker
  file:
    path: /etc/docker
    owner: root
    group: root
    mode: '0755'
    state: directory
- name: /etc/docker/daemon.json
  copy:
    dest: /etc/docker/daemon.json
    owner: root
    group: root
    mode: '0644'
    content: '{"iptables":false}'
- name: Docker
  apt:
    name: docker-ce
- name: Docker compose
  apt:
    name: docker-compose

archivos/firewall/rules.v4

*filter
:INPUT DROP [0:0]
:FORWARD DROP [0:0]
:OUTPUT ACCEPT [0:0]
-A INPUT -d 127.0.0.0/8 ! -i lo -j DROP
-A INPUT -i lo -j ACCEPT
-A INPUT -p tcp -m tcp --dport 22 -j ACCEPT
-A INPUT -m conntrack --ctstate ESTABLISHED,RELATED -j ACCEPT
-A FORWARD -o docker1 -d 192.168.234.2/32 -p tcp -m tcp --dport 80 -j ACCEPT
-A FORWARD -i docker1 -o eth0 -j ACCEPT
-A FORWARD -m conntrack --ctstate ESTABLISHED,RELATED -j ACCEPT
COMMIT

*nat
:PREROUTING ACCEPT [0:0]
:INPUT ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
:POSTROUTING ACCEPT [0:0]
-A PREROUTING -i eth0 -d 78.47.124.58 -p tcp -m tcp --dport 80 -j DNAT --to 192.168.234.2
-A POSTROUTING -o eth0 ! -s 78.47.124.58 -j MASQUERADE
COMMIT

archivos/firewall/rules.v6

*filter
:INPUT DROP [0:0]
:FORWARD DROP [0:0]
:OUTPUT ACCEPT [0:0]
-A INPUT -d ::1/128 ! -i lo -j DROP
-A INPUT -i lo -j ACCEPT
-A INPUT -p tcp -m tcp --dport 22 -j ACCEPT
-A INPUT -m conntrack --ctstate ESTABLISHED,RELATED -j ACCEPT
-A FORWARD -o docker1 -d 64:ff9b::192.168.234.2 -p tcp -m tcp --dport 80 -j ACCEPT
-A FORWARD -i docker1 -o eth0 -j ACCEPT
-A FORWARD -m conntrack --ctstate ESTABLISHED,RELATED -j ACCEPT
COMMIT

*nat
:PREROUTING ACCEPT [0:0]
:INPUT ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
:POSTROUTING ACCEPT [0:0]
-A PREROUTING -i eth0 -d 2a01:4f8:c0c:3bc1::/64 -p tcp -m tcp --dport 80 -j DNAT --to 64:ff9b::192.168.234.2
-A POSTROUTING -o eth0 ! -s 2a01:4f8:c0c:3bc1::/64 -j MASQUERADE
COMMIT

archivos/nginx-site.conf

server {
    listen       80;
    listen       [::]:80;
    server_name  localhost;

    location / {
        root   /usr/share/nginx/html;
        index  index.html index.htm;
    }

    error_page   500 502 503 504  /50x.html;
    location = /50x.html {
        root   /usr/share/nginx/html;
    }
}

archivos/docker-compose.servicio

[Unit]
Requires=docker.service

[Service]
Type=oneshot
RemainAfterExit=yes
WorkingDirectory=/usr/local/docker-services
ExecStart=/usr/bin/docker-compose up -d --force-recreate
ExecStop=/usr/bin/docker-compose down

[Install]
WantedBy=multi-user.target

Answer 1

Mi conjetura es que las reglas de su firewall IPv6 están bloqueandoNDP (Protocolo de descubrimiento de vecinos)paquetes, impidiendo así que su host resuelva correctamente la dirección de la capa de enlace del contenedor.

En la pila IPv4, la resolución de las direcciones de la capa de enlace (Ethernet) es manejada porARP (Protocolo de resolución de direcciones), que funciona utilizando direcciones de capa de enlace como destinos de paquetes. Cuando un host emite solicitudes ARP o anuncios ARP no solicitados, esos paquetes se reenvían directamente a la dirección de la capa de enlace de transmisión (que está FF:FF:FF:FF:FF:FFen el protocolo Ethernet) y, por eso, no están sujetos a iptablesfiltrado.

En la pila IPv6, la resolución de las direcciones de la capa de enlace se maneja mediante NDP (Protocolo de descubrimiento de vecinos). A diferencia de ARP, los paquetes NDP en realidad son paquetes ICMPv6 reenviados a direcciones IPv6 y, como resultado, están sujetos a ip6tablesfiltrado.

Creo que, según mi experiencia y como se ve enArtículo Wiki de Arch Linux, el módulo CONNTRACK no está diseñado para rastrear paquetes NDP ICMPv6 y marcar paquetes de respuesta comoESTABLECIDOoRELACIONADO. Mi sugerencia es permitir dicho tráfico explícitamente en files/firewall/rules.v6el archivo:

(nuevas reglas)

-A INPUT -i docker1 -p ipv6-icmp -m icmp6 --icmpv6-type 133 -m comment --comment router-solicitation -j ACCEPT
-A INPUT -i eth0 -p ipv6-icmp -m icmp6 --icmpv6-type 134 -m comment --comment router-advertisement -j ACCEPT
-A INPUT -p ipv6-icmp -m icmp6 --icmpv6-type 135 -m comment --comment neighbor-solicitation -j ACCEPT
-A INPUT -p ipv6-icmp -m icmp6 --icmpv6-type 136 -m comment --comment neighbor-advertisement -j ACCEPT

(archivo completo)

*filter
:INPUT DROP [0:0]
:FORWARD DROP [0:0]
:OUTPUT ACCEPT [0:0]
-A INPUT -d ::1/128 ! -i lo -j DROP
-A INPUT -i lo -j ACCEPT
-A INPUT -p tcp -m tcp --dport 22 -j ACCEPT
-A INPUT -m conntrack --ctstate ESTABLISHED,RELATED -j ACCEPT
-A INPUT -i docker1 -p ipv6-icmp -m icmp6 --icmpv6-type 133 -m comment --comment router-solicitation -j ACCEPT
-A INPUT -i eth0 -p ipv6-icmp -m icmp6 --icmpv6-type 134 -m comment --comment router-advertisement -j ACCEPT
-A INPUT -p ipv6-icmp -m icmp6 --icmpv6-type 135 -m comment --comment neighbor-solicitation -j ACCEPT
-A INPUT -p ipv6-icmp -m icmp6 --icmpv6-type 136 -m comment --comment neighbor-advertisement -j ACCEPT
-A FORWARD -o docker1 -d 64:ff9b::192.168.234.2 -p tcp -m tcp --dport 80 -j ACCEPT
-A FORWARD -i docker1 -o eth0 -j ACCEPT
-A FORWARD -m conntrack --ctstate ESTABLISHED,RELATED -j ACCEPT
COMMIT

*nat
:PREROUTING ACCEPT [0:0]
:INPUT ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
:POSTROUTING ACCEPT [0:0]
-A PREROUTING -i eth0 -d 2a01:4f8:c0c:3bc1::/64 -p tcp -m tcp --dport 80 -j DNAT --to 64:ff9b::192.168.234.2
-A POSTROUTING -o eth0 ! -s 2a01:4f8:c0c:3bc1::/64 -j MASQUERADE
COMMIT