Help with Firewall and Networking


I am trying to run a Docker container system on CentOS 9 Stream.

The ctfd application container is unable to connect to db with error of “No route to host”

Here is an entry from journalctl -xe

Dec 23 11:08:16 host kernel: filter_FWD_public_REJECT: IN=br-517219210dc2 OUT=br-517219210dc2 PHYSIN=vethdb4e203 PHYSOUT=vethd3e2d48 MAC=02:42:ac:16:00:04:08:00 SRC= DST= LEN=60 TOS=0x00 PREC=0x00 TTL=64 ID=16578 DF PROTO=TCP SPT=36826 DPT=3306 WINDOW=64240 RES=0x00 SYN URGP=0

Would appreciate help on where to start.

I don’t have experience with Centos Stream 9, but I would search for “Centos stream firewall” on Google. Centos uses firewald for firewall. You can disable it or configure it properly. You could also search for “firewalld centos docker”. I found this

It is about Centos 7, but I guess it would be similar on Centos Stream 9.