docker containers can't ping each other using CNI bridge (same host)

I'm trying to use the bridge CNI plugin with a standalone kubelet and I'm unable to ping pods from each other (same node).

I'm able to ping a pod from the host and from the pod itself (using its subnet IP).

Also, packets from the "caller" pod reach the bridge : 10:28:00.951871 IP ip-10-0-1-4.eu-west-3.compute.internal > ip-10-0-1-5.eu-west-3.compute.internal: ICMP echo request, id 15, seq 22, length 64

but not the other pod's interface (tcpdump doesn't see any ping).

the pod I try to reach has the 10.0.1.5 IP address (I'm able to ping it there from host and from itself)

cni config :

{ "cniVersion": "0.3.1", "name": "bridge", "type": "bridge", "bridge": "cnio0", "isGateway": true, "ipMasq": true, "ipam": { "type": "host-local", "ranges": [ [{"subnet": "10.0.1.0/24"}] ], "routes": [{"dst": "0.0.0.0/0"}] } } 

brctl shows that the 2 veth pairs are actually connected to the bridge.

I also tried to add the firewall CNI plugin, and load it after the bridge, without more success...

Is there something else I have to configure in order to get it working ?