NAT Address Mapping function lets you specify the outgoing IP address(es) for one internal IP address or a block of internal IP addresses.
Now, Vigor2950 and VigorPro 5510 Series support this feature. We will take an example to introduce how to make use of this feature. The scenario is shown below, with a Vigor2950 involved. Both WAN connections are active and the WAN1 connection has 3 IP addresses.
Address Mapping
Main WAN IP address is 172.17.1.53.
The other two are 172.17.1.55 and 172.17.1.57 that set in the WAN1 IP Alias. Make sure Join IP NAT Pool is not checked.
The outgoing traffic is routed to WAN1 port or WAN2 port according to the Load-balance policy. When the traffic is routed to WAN1 port, by default WAN1 main IP address (172.17.1.53 in this example) is used to replace the source private IP address. Therefore, all the client IP addresses will be transmitted to 172.17.1.53 by default.
Since you have additional IP addresses on WAN1 connection, you may want some of the internal PCs be presented to the Internet with different IP addresses. In this example, the server with IP address 192.168.1.11 is to be presented to the Internet as 172.17.1.57 and the computers with a block of IP addresses from 192.168.1.16 through 192.168.1.31 are to be presented as 172.17.1.55.
Please go to the NAT >> Address Mapping. Pay special attention to the Mask setup.
Click Index number 1 and 2 to configure the details.
Here the Private IP can be any IP address within the range of 192.168.1.16 through 192.168.1.31. The Subnet Mask defines the size of the IP range, and the Private IP is an indicator of the IP range. Therefore, the combination of Private IP and Subnet Mask determine the IP range.
Upon completing the above configuration, you have specified the outgoing IP address(es) for some specific computers. But you still have to specify the outgoing interface for them. Otherwise, the traffic may be routed out with IP address 172.17.1.55 or 172.17.1.57 through WAN2 port. The load-balance policies are below.
Click Index number 1 and 2 to configure the details. Make sure Auto failover to the other WAN is unchecked.
And