Given the interfaces on a firewall:

eth0 Link encap:Ethernet HWaddr 02:40:67:34:F5:47
inet addr:192.168.0.1 Bcast:192.168.0.255 Mask:255.255.255.0

eth1 Link encap:Ethernet HWaddr 86:23:98:45:35:56
inet addr:123.45.240.69 Bcast:255.255.255.255 Mask:255.255.252.0

eth2 Link encap:Ethernet HWaddr 86:23:98:45:35:56
inet addr:123.45.240.70 Bcast:255.255.255.255 Mask:255.255.252.0

eth3 Link encap:Ethernet HWaddr 12:73:00:c4:47:56
inet addr:192.168.1.1 P-t-P:192.168.1.2 Mask:255.255.255.255

and the routing table:
Destination Gateway Genmask Iface
192.168.1.2 0.0.0.0 255.255.255.255 eth3
192.168.0.0 0.0.0.0 255.255.255.0 eth0
123.45.240.0 0.0.0.0 255.255.0.0 eth1
123.45.240.0 0.0.0.0 255.255.254.0 eth2
131.244.0.0 0.0.0.0 255.254.0.0 eth3
0.0.0.0 203.45.240.1 0.0.0.0 eth1



If I want to determine the interface which following packets:

SRC ADDR DST ADDR
192.168.0.3 123.45.241.30
240.18.10.3 131.244.12.23
10.4.5.6 10.4.5.7


what is the interface for these three pairs? and the most important thing is how to recognize it?