“no route to host” issue

Tried this but not worked for no route to host from inside Docker container on the same host:

$ sudo sysctl net.bridge.bridge-nf-call-iptables=0
$ sudo sysctl net.bridge.bridge-nf-call-arptables=0
$ sudo sysctl net.bridge.bridge-nf-call-ip6tables=0

This command alone also not worked:

$ sudo firewall-cmd --add-masquerade

I suspect that add-masquerade might affect how proxy_protocol interprets real client IP.