ZyXEL Communications P-660H-Tx v2 - Manual (Page 298)

Appendix H Triangle Route
P-660H-Tx v2 User’s Guide
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Figure 172 “Triangle Route” Problem
The “Triangle Route” Solutions
This section presents you two solutions to the “triangle route” problem.
IP Aliasing
IP alias allows you to partition your network into logical sections over the same Ethernet
interface. Your ZyXEL Device supports up to three logical LAN interfaces with the ZyXEL
Device being the gateway for each logical network. By putting your LAN and Gateway B in
different subnets, all returning network traffic must pass through the ZyXEL Device to your
LAN. The following steps describe such a scenario.
1 A computer on the LAN initiates a connection by sending a SYN packet to a receiving
server on the WAN.
2 The ZyXEL Device reroutes the packet to Gateway A, which is in Subnet 2.
3 The reply from WAN goes through the ZyXEL Device to the computer on the LAN in
Subnet 1.
Figure 173 IP Alias