docker stack 容器互 ping 不通

docker stack 容器互 ping 不通，会有什么原因导致的？

端口开通了

firewall-cmd --zone=public --add-port=2377/tcp --permanent
firewall-cmd --zone=public --add-port=7946/tcp --permanent
firewall-cmd --zone=public --add-port=7946/udp --permanent
firewall-cmd --zone=public --add-port=4789/tcp --permanent
firewall-cmd --zone=public --add-port=4789/udp --permanent
firewall-cmd --reload

docker-compose.yml 配置

version: '3.7'

services:
  busybox:
    image: busybox
    command: ping www.baidu.com
    networks:
      - multi
    deploy:
      replicas: 2
networks:
  multi:
    external: true
    name: multi