no communication between docker containers

[arenevier]

Hi,

I have ufw installed with no extra configuration. I tried to follow the instructions. According to https://github.com/chaifeng/ufw-docker/#how-it-works,

The following rules allow the private networks to be able to visit each other

my understanding is that docker containers should be able to communicate with access each other.

I have dockerA which contains a reverse proxy from to another service running in dockerB. When dockerA tries to connect to dockerB, the connection is blocked.

Logs show:

[UFW BLOCK] IN=br-d3c6d78ed61b OUT= PHYSIN=veth0728c11 MAC=02:42:54:5b:9b:aa:02:42:ac:12:00:02:08:00 SRC=172.18.0.2 DST=172.17.0.1 LEN=60 TOS=0x00 PREC=0x00 TTL=64 ID=44854 DF PROTO=TCP SPT=40668 DPT=3040 WINDOW=64240 RES=0x00 SYN URGP=0
[UFW BLOCK] IN=br-d3c6d78ed61b OUT= PHYSIN=veth0728c11 MAC=02:42:54:5b:9b:aa:02:42:ac:12:00:02:08:00 SRC=172.18.0.2 DST=172.17.0.1 LEN=60 TOS=0x00 PREC=0x00 TTL=64 ID=44855 DF PROTO=TCP SPT=40668 DPT=3040 WINDOW=64240 RES=0x00 SYN URGP=0