Viper User
Manual (001-5008-000 Rev6)
Page
71
hidden. In this example, remember that Host 172.31.5.2 thinks the IP packets are coming
from 10.0.14.203.
Figure 7.18 NAT on Viper: Port 2000 is redirected to 192.168.205.125:23
When Host 172.31.5.2 wants to send packets to Host 192.168.205.2 the packets are sent to
10.0.14.203. NAT port translation allows Host 172.31.5.2:1435 (port 1435) to send TCP
packets to 192.168.205.5:23 (port 23) by sending the packets to 10.0.14.203:2000 (port
2000). Figure 7.19 shows how the packets would be modified as they moved through the
network.
Figure 7.19 Packet flow, Port redirection
Packet (1)
Source Address
172.31.5.2:1435
Destination Address
192.168.205.2:23
Packet (1)
Source Address
172.31.5.2:1435
Destination Address
10.0.14.203:2000
Packet (1)
Source Address
172.31.5.2:1435
Destination Address
10.0.14.203:2000
Host 1
192.168.205.2
Host 2
172.31.5.2
Viper 1
NAT enabled, Eth is private
Port 2000 translate to Port 23
Viper 2
NAT disabled
Private Network
RF Network
Eth: 172.31.5.1
RF: 10.0.14.203
Port 2000
RF: 10.0.14.186
Eth: 192.168.205.1
Host 2
Eth: 172.31.5.2
Port 1435
Viper (2)
(NAT disabled)
Private Network
Host 1
Eth: 192.168.205.2
Port 23
Public Network
RF Network
Viper (1)
(NAT enabled,
Ethernet Interface is private, Port redirected)