FYI...network gateways are not used at all if the other end you're trying to access is in the same subnet. It does not matter if you're using a cross-over cable, a router, hub, or switch.
In plain English, here's an example of a configuration that's in the same subnet:
PC IP Address: 192.168.1.1
PC Subnet Mask: 255.255.255.0
PS2 IP Address: 192.168.1.2
PS2 Subnet Mask: 255.255.255.0
Any device whose IP address is in the range of 192.168.1.1 to 192.168.1.254 will be in the same subnet in this example. If and only if you need to go beyond this range will you need a network gateway (router) IP address.
PS2 NTSC US V1 | PS2 Network Adapter | Maxtor MaXLine Plus II 250gb HD | Matrix Infinity v1.38
PS3 Slim | WD Scorpio Blue 750GB Internal | WD Essential USB 3.0 2TB