Re: One way pings
the KB shows external to internal IPs, but you can apply this KB to internal (or local) subnets. basically, it's doing static NAT between your 2 networks.
But, from what you request at the beginning of the post, you need to access server B (192.168.10.30) from server A (172.18.1.10) , which are located on subnetB (192.168.10.10 on the FGT) and subnetA (172.18.1.1 on the FGT).
* serverB: configure either a defaut route, or a /32 route to 172.18.1.10 through 192.168.10.10
* serverA: configure either a default route, or a /32 route to 192.168.10.30 through 172.18.12.10
* configure firewall policy or policies if both networks can be source network. If you don't use NAT, then your original ports will be kept. Otherwise, you can follow the KB, and have static NAT.