Docker creates two bridges within the host. Why can’t containers in two bridges ping each other? How can I set them to ping each other?

  docker, question

Each container is added to only one bridge.
The system is ubuntu16.04, which uses the default operation and has no special settings.

No one answered the question and was trampled.

Answer by yourself:
Docker writes the rules in iptables. Restrict mutual access of containers under different bridges. Just delete this restriction rule.