Using IP Alias
In a typical environment, a LAN router is required to connect two local networks. The ZyWALL supports to connect three local networks to the ISP or a remote node, we call this function as 'IP Alias'. In this case, an internal router is not required. For example, the network manager can divide the local network into three networks and connect them to the Internet using Prestige's single user account. See the figure below.
The ZyWALL supports three virtual interfaces on LAN and DMZ ports via its single physical Ethernet interface. The first network can be configured in NETWORK->LAN (and NETWORK->DMZ) as usual. The second and third networks that we call 'IP Alias 1' and 'IP Alias 2' can be configured in NETWORK->LAN->IP Alias (and NETWORK->DMZ>IP Alias).
There are three internal virtual LAN interfaces for the ZyWALLto route the packets from/to the three networks correctly. They are enif0 for the major network, enif0:0 for the IP alias 1 and enif0:1 for the IP alias 2. Therefore, three routes are created in the ZyWALL as shown below when the three networks are configured. If the ZyWALL's DHCP is also enabled, the IP pool for the clients can be any of the three networks.
| Copyright (c) 1994 - 1999 ZyXEL Communications Corp. ras> ip ro st Dest FF Len Interface Gateway Metric stat Timer Use 192.168.3.0 00 24 enif0:1 192.168.3.1 1 041b 0 0 192.168.2.0 00 24 enif0:0 192.168.2.1 1 041b 0 0 192.168.1.0 00 24 enif0 192.168.1.1 1 041b 0 0 ras> |
Two new protocol filter interfaces in SMT menu 3.2.1 allow you to accept or
deny LAN packets from/to the IP alias 1 and IP alias 2 go through the ZyWALL.
The filter set in menu 3.1 is used for main network configured in menu 3.2.
1. Edit the first network in menu 3.2 by configuring the ZyWALL's first LAN IP address.
Key Settings:
| IP Address | Specify the IP address you would like to assign to the LAN interface. This will create the first route in the enif0 interface. |
2. Edit the second and third networks in NETWORK->LAN->IP Alias
Key Settings:
| IP Alias 1 | Toggle to 'Yes' and enter the second LAN IP address for the ZyWALL. This will create the second route in the enif0:0 interface. |
| IP Alias 2 | Toggle to 'Yes' and enter the third LAN IP address for the ZyWALL. This will create the third route in the enif0:1 interface. |
All contents copyright (c) 2003 ZyXEL Communications Corporation.