Chapter 6 Tutorials
ZyWALL USG 1000 User’s Guide
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Figure 102 Create a Policy Route
Now the LAN SMTP server replies to the ZyWALL’s LAN IP address and the ZyWALL
changes the source address to 1.1.1.1 before sending it to the LAN user’s computer. The
source in the return traffic matches the original destination address (1.1.1.1) and the LAN user
can use the LAN SMTP server.
Figure 103 NAT Loopback Successful
192.168.1.21
LAN
192.168.1.89
Source 1.1.1.1
SMTP
NAT
Source 192.168.1.21
SMTP