Packets marked INVALID in FORWARD rule
- by Raphink
I have a firewall that has 3 IP aliases on 1 physical interface. Packets get dropped between these 3 interfaces (either ICMP, HTTP, or anything else). We tracked it down to these packets being marked INVALID in the FORWARD rule and dropped due to the this rule:
chain FORWARD {
policy DROP;
# connection tracking
mod state state INVALID LOG log-prefix 'INVALID FORWARD DROP: ';
mod state state INVALID DROP;
mod state state (ESTABLISHED RELATED) ACCEPT;
}
(That is, we see the INVALID FORWARD DROP logs in dmesg)
What could be causing this?