Problem to call loki from other instance in swarm

Hello I try to monitor docker swarm cluster with grafana + loki + promtail but I have problem : loki only listen on tcp6 protcol.
I have two instances in oracle cloud in the same private network, I’m able to ping each other but port 3100 was unreachable because first instance only listen tcp6 port.

tcp6       0      0 :::3100                 :::*                    LISTEN

To connect node to loki (in master node) I use loki docker plugin with this configuration :

    "debug" : true,
    "log-driver": "loki",
    "log-opts": {
        "loki-url": "",
        "loki-batch-size": "400"

Do you have any solutions or maybe another way to monitor the logs of all my containers in docker swarm cluster.

Perhaps your default NIC is ipv6? Check your NICs on your host and try using instance_interface_names to force Loki to use IPv4 NIC.