Sometimes you do net get an IP automatically. But this is not a big problem. You can add IP addresses and routes manualy.
You can use the “Network Manager” –> “Open Network Prefereneces”
But I prefer the shell commands.
Verify that you can access the corresponding external / internal routing interface and add a route to that specific network:
Adding a specific host route:
sudo route add -host 18.104.22.168 192.168.1.254
Adding a specific network route:
sudo route add -net 192.168.2.0 192.168.1.254 -netmask 255.255.255.0
You see that the syntax is turned:
route add [-net|-host] [TARGETIP] [GATEWAY] -netmask [SUBNET]
To see the routing table
Remember to add a host / net route on the corresponding client as well if it is not handled by the default gateway.