Incoming WAN Address Route to 2nd Firewall

Hi there,

We have 2 firewalls in our office. FW1 and FW2

On FW1, lives most of the main LAN networks and services, with FW2 being a backup (and as such, has a different WAN internet line coming into it)

So I'm trying to route traffic to WAN IP 2 (which lives on FW2) which has a NAT rule configured on it to resolve to an internal IP address on FW1 (192.168.x.x)

That works as far as FW2 goes, but FW1 blocks the connection with the following error:

DROPPED, Drop Code: 30(Syn Flood Protection), Module Id: 25(network)

Tried calling support, who spent an hour looking into the issue, but was unable to resolve

Any ideas?

Cheers