There is a known issue with RHEL8/CentOS Stream 8 when Docker swarm overlay network configuration breaks when the
outside network maximum transmission unit (mtu) is smaller than the default value. The
mtu is the maximum
size of the packet that can be transmitted from a network interface.
When deploying a multinode configuration on RHEL 8/CentOS Stream 8, run the following steps:
Check mtu for docker0 and eth0 using
ifconfig | grep mtu.
Set the docker0 mtu value to be equal to
sudo ifconfig eth0 mtu 1500. Make sure to set the command on all nodes and also after each virtual machine reboot.